I agree there is some good advice on here but it's a bit off-putting to be told you have to know everything before you buy.
You have to start somewhere.
Most people of a certain age, like another here and myself who started astronomy young, started with far worse telescopes than any of those on your list because it cost more than a month's pay to buy one!
If you wanted a good telescope in those days you made your own or bought second hand if you were lucky enough to know somebody who had one for sale.
And we didn't have go-to telescopes with computer control.
We learned our way round the sky.
You might not make the wisest choice for your first telescope but you'll have one, and it will still be useful later even if you buy a better one.
So don't worry too much, but you'll still be better off knowing one or two bits first.
So, those telescopes.
None of them is rubbish, but neither are they particularly great.
All are low to mid price and will show a fairly sharp view of a lot of objects, but not at huge magnifications like some silly adverts say about telescopes.
About 25 per inch of aperture is what most telescopes can do, but you can double that for easier viewing so 50 per inch of aperture is often quoted.
So a six-inch does 150x and you can use 300x to see the detail easier but the mounting and the eyepiece and everything else about the telescope and the quality of the sky has got to be really good to use that high a power. Most nights in UK even 200x is pretty tough going for a six inch telescope or any other.
Lists of what magnification and resolution tescopes can achieve for their size are on here with much other useful information.
http://www.ayton.id.au/gary/Science/Astronomy/Ast_Telescope.htm . . . .
For planets a long focus objective lens or mirror of F/8 or above is much better than a short focus one, but for star clusters and the larger nebulae a short focus of f/6 or below gives a brighter image and better views. Catatadioptric telescopes like the Maksutov and Cassegrain have a high F-ratio and are better for planets and for medium and high power views of small bright nebulae and tight double stars.
Many people have two or more telescopes to cover different aspects of observing,
A small short focus refractor for star fields and clusters and generally sweeping around to admire the view, and a long focus refractor or a Newtonian or Maksutov for planets.
Equatorial mounts are not difficult to use but since John Dobson designed his simple and easily-made mount some people now think equatorials are somehow more complicated and advise Dobsonian mounts to be used. but their chief advantages in use are compactness and the ability to mount a large telescope at a low level for convenience of eyepiece height without using steps or a box to stand on, and they are only of use for Newtonian reflectors although vey large Newtonians of course will still need steps or a box for observing objects high in the sky.
http://www.areavoices.com/astrobob/images/Tele1_Me_1.jpg . . . . .
http://www.ct-astronomer.com/images/stellafane2001_5med.jpg . . .
The Skywatcher is reasonable value for money for a budget telescope.
You can get it from Warehouse Express or many other outlets.
Seben are sold by a German company only on Ebay and are the same as so many others but with the Seben name on and mostly have Chinese optics made by Synta, who also make the same lenses for Skywatcher and Helios telescopes. and the cheaper end of the Celestron range.
The Celestron and Helios 80mm F/6 refractors are the same telescope with different cosmetics and prices.
The real nice UK firm is Orion, who make lovely telescopes but they maybe cost more than you want to pay.
There is an American optics firm called Orion as well, but they are NOT the same company, so be careful about mixing them up.
I have two skywatcher refractors and they are OK for what I want them for. Not tops, but OK for the money. Thousands of amateur astronomers use Skywatcher telescopes.
On here, menu left, right down the bottom to the astronomy section ....click on tescopes....then reflectors
you'll see lots of them including skywatcher.
Then go to telescopes...refractors....lots more scopes
http://www.warehouseexpress.com/Home/default.aspx . . . .
Orion telescopes, UK....very nice....gimme,gimme,haha
Just maybe a bit expensive but you'll see what there is from a very good and respected British company.
I've got a big blank pyrex glass disc still waiting to be made into a telescope mirror, very nice price from Orion Optics, ordered at their trade stand in London at Astrofest, but that''s a long winter evenings job for me. Stopped for the summer...finished by next summer.
The Astrofest exhibition is the place to be every Febuary to see the real stuff and have a heart attack over the prices of the big stuff!
This is how rough it can get for a mid-aperture decent scope
http://farm4.static.flickr.com/3379/3261007537_6059acfd95.jpg?v=0 . . .
.http://images.google.com/imgres?imgurl=http://www.astronomynow.com/european_astrofest_2009_blog/assets_c/2009/02/IMG_0154-thumb-300x225-89.jpg&imgrefurl=http://www.astronomynow.com/european_astrofest_2009_blog/2009/02/new-range-of-skywatcher-at-optical-vision.html&usg=__QSyQ6Mep_PFZYP0q7zn9izT9Gto=&h=225&w=300&sz=45&hl=en&start=56&um=1&tbnid=6Lxz_THX6eJCdM:&tbnh=87&tbnw=116&prev=/images%3Fq%3Dastrofest%2B2009%26ndsp%3D20%26hl%3Den%26rls%3Dcom.microsoft:en-gb:IE-SearchBox%26rlz%3D1I7GPEA%26sa%3DN%26start%3D40%26um%3D1 . . .
The best of the top-quality refractor telescopes of 6 inches aperture can cost more than three times that, with no mounting!
.Lovely show! It's organised by Astronomy Now magazine which you can get in W.H.Smiths or other newsagents.
http://www.orionoptics.co.uk . . . .
http://www.astronomynow.com/astrofest . .
Lots of good links if you scroll right down on here to the black area, and it's got Skywatcher and Orion telescope reviews too,,
,http://www.astronomyforum.net/uk-astronomy-forum/82590-astrofest-2009-a.html . . . .
Oh, and don't believe that everybody on Ebay is a crook or untrustworty or is selling only junk!
Ebay doesn't sell anything. People do, and the comments on here are as bad as saying that all Liverpool people are crooks or all London people sell junk.
No better than racist comments actually.
To say that all Ebay sellers are untrustworthy is doing an injustice to the many good people who use Ebay to sell things.
I bought a very good 8-inch Maksutov and made a good friend when we met to complete the sale, since I don't live in UK all the time and had made a trip to pick it up.
He is secretary of an Astronomy club in a well known city in England and a very good one too!
If he didn't sell it on Ebay but through an astronomy forum or the club notice board would it be a worse telescope?
Would he be a worse person or the same one?
You have to be careful obviously, but not everything on Ebay or Craigs List or any other site is necessarily junk.
Astrophotography is not necessarairily very difficult or expensive. 35mm SLR camera adaptors for standard telescope focusers can be bought from many firms and the cameras are now very cheap second hand. It needs to have a cable release and time exposure capalility, and a mirror lock is very useful to avoid vibrations.
A web cam can be used and the images processed with Registax (free download) and photoshop or similar.
I bought a Minolta 300x for £5 last week, with a 28-70mm lens, from a charity shop, a nice present for somebody starting photography and home developing and printing.
A camera mounted directly on a motor driven mount does very well, with a telescope mounted next to it it for a guide scope. The camers can also be piggy-bcked onto the telescope.
Many of the best amateur photos of large nebulae are done that way. Lenses from 20mm to 300mm are commonly used.
http://www.eskimo.com/~rachford/widefield/targets.html . .
http://www.covingtoninnovations.com/astro/exhibit.html . . .
Here are two telescope questions with some information you may find useful.
https://answersrip.com/question/index?qid=20090817143947AA9dZzS . . . . .