Dobsonian telescopes are a great place to start IMO. The simple mount means you get more bang for your buck with the actual scope. There are two main types of mount, alt-azimuth and equatorial. With an alt-azimuth mount, you rotate the scope left-right and up-down (Dobsonians fall into this category). With an equatorial mount, you basically align the mount with North star and this means you only need to move the scope side to side. While this is obviously a better solution for following objects, the mounts bump the price up and it also requires aligning every time you want to use the thing. A sure-fire way to get a kid bored of using it IMO.
The other category to worry about is the type of scope itself, mainly broken down into reflectors (these use a mirror to focus light) and refractors (these use a lens to focus light). Once you get above a certain aperture, refractors get costly very quickly due to ease of manufacturing of large mirrors vs large lenses I imagine.
I'm sure there are much more knowledgeable & experienced people here than I who may be able to offer some more detailed advice. But feel free to fire over any questions you might have.
Btw I have the slightly larger version of the above scopes (the 130p) and I'm a big fan. Takes no time at all to set up which is one of the main advantages in my book.
Edit: Just re-read your comment and spotted it was for a 3 1/2 year old, for some reason I misread it as older originally. Most of the detail up there is probably largely redundant but I still stand by getting a simple scope like the little Dobsonian up there.
I'd recommend one of these two, depending on which fits your budget best:
http://www.opticalvision.co.uk/beginners-telescopes/heritage-100p_dobsonian.html
http://www.opticalvision.co.uk/astronomical_telescopes-sky-watcher-sky-watcher_iya_2009_special_edition_telescopes/hertiage-76.html
Dobsonian telescopes are a great place to start IMO. The simple mount means you get more bang for your buck with the actual scope. There are two main types of mount, alt-azimuth and equatorial. With an alt-azimuth mount, you rotate the scope left-right and up-down (Dobsonians fall into this category). With an equatorial mount, you basically align the mount with North star and this means you only need to move the scope side to side. While this is obviously a better solution for following objects, the mounts bump the price up and it also requires aligning every time you want to use the thing. A sure-fire way to get a kid bored of using it IMO.
The other category to worry about is the type of scope itself, mainly broken down into reflectors (these use a mirror to focus light) and refractors (these use a lens to focus light). Once you get above a certain aperture, refractors get costly very quickly due to ease of manufacturing of large mirrors vs large lenses I imagine.
I'm sure there are much more knowledgeable & experienced people here than I who may be able to offer some more detailed advice. But feel free to fire over any questions you might have.
Btw I have the slightly larger version of the above scopes (the 130p) and I'm a big fan. Takes no time at all to set up which is one of the main advantages in my book.
Edit: Just re-read your comment and spotted it was for a 3 1/2 year old, for some reason I misread it as older originally. Most of the detail up there is probably largely redundant but I still stand by getting a simple scope like the little Dobsonian up there.