If you really get serious, consider some kind of CCD imaging system. Its more or less the standard when it comes to capturing astro images. But keep a good set of long eye relief (lets you hold your eye back from the eyepiece a comfortable distance) eyepieces for "live" viewing. The neighbors (especially kids) will love that.
You could make a 10” diameter Dobson telescope for about $500 if you wanted to put the time in to construct it.
You may find a local astronomy club in your area, they can also assist you in your selection.
http://www.astronomyclubs.com/country/United%20States
http://www.skyandtelescope.com/community/organizations
www.oriontelescope.com.......Great selections....
At that price, forget the refractors if you cannot settle for binoculars, because the Wal Mart style thin refracting tubes are not worth it for serious stuff, imo, and the binoculars do a better quicker job to learn the sky.
Get a Newtonian reflector. I prefer Equatorial mounts but Dobsonian mounts are cheaper.
In order of brand quality, imo,
Celestron
Meade
Konus-Orion
In order of Bang for Buck optics quality:
Newtonian (pure reflector)
Shmidt Cassegrain, Shmidt “Kasuetov” (hybrid reflectors-refractors)
Refractor
In order of raw quality refractors might be arguably the best for color etc... but they are so much more expensive, it is not worth it, imo.
A big fat light-hugging Newtonian scope makes amateurs so thrilled to see their first deep sky objects like Nebulas, galaxies etc... and all for $500 you get some high quality images.
Motors can be an extra cost. I would not trade glass or quality for a motor, though. I’d rather learn to do it manualy. The thrill is even more then, and motors are not necessarily hassle free to set up and work unless you go serious with photography exposure etc... but that requires much more than $500.
Also get scopes that accept large eyepieces for good eye relief.
Look for one that let’s you see things that are really far away. Try to find one you can use for reading, as well. You might also want to consider a monocle.
I would be careful that this is something HE wants and not something that you think is cool.
I have every hobby ever - and my wife got me some junky telescope a few years back. It never gets used.
And I can get interested in anything.
One thing - along a similar axis - that I like doing for fun is celestial navigation with a sextant. Plus - you still need to learn stars etc.
For the Telescope - from the ground up -
1. Base/support/tripod - whatever they call it.
2. Mount - that follows target
3. Computer controller - a must in the modern world. 100X easier.
4. Telescope
5. Eyepiece.
The chain is only as strong as weakest link.
There are a lot of nice sets of gear - but I have fun with binoculars.
Oh - also - Starry Night software for computer. Can stargaze “from the desktop”. A lot of fun for about $20. Put it on a laptop, go out in the woods/country, and pretend you have a telescope.
With that and a sextant - you are approaching guy-geek nirvana.
Bfl
Bttt.
BFL
The best one to get is the one that will get the most use.
I’d also suggest a chair or stool that will offer the best viewing comfort for whatever type of scope and mount you end up getting.
Go to THIS LINK and save yourself a lot of money on a really good 'first scope.'
Normally going for about $500, this Celestron has on-board computer control, free shipping, all for $289.95. That is pretty hard to beat. 8^)
Beat thing to do is go to amazon and browse the buyer/user ratings of telescopes in your price range, both positive and negative comments.
As others have said it depends on what you want to watch, the range of choices is vast.