Roll up your sleeves
Visually, in ceiling speakers are even more unobtrusive than in wall speakers and newer models sport individually adjustable woofers and tweeters for better sound distribution. Don't get too excited, though. It is recommended that for a completely integrated, embedded system of speakers, you use both wall and ceiling units. Ceiling-mounted front speakers can't project sound as if coming from a television or big screen.
Rock steady
To be safe, go with the comfortable standard brand, Speakercraft. They make an AIM line for about $400 a pair that are easy to install and sound great. If you think you're up to the task yourself, read on. You'll know by the end if you pass muster on the handyman scale.
1. Get out your stud detector and mark all your preferred speaker spots.
2. Take the cardboard template from the Speakercraft box and measure to make sure they will sit equidistance from walls and corners. Pencil in a dot marking the center in the ceiling.
3. There may be stuff in the ceiling that would get in the way of the speaker. Bend a heavy wire the radius of your speaker. Stick it in the ceiling to the height of the speaker and spin it. If you hit something, repeat steps two and three. Be prepared to make a few unnecessary holes.
4. Barring any obstructions, staple your template in place and trace it. Cut out a hole using a wallboard knife.
5. With a fiberglass fish tape, push your speaker wire to the desired location. Depending on the complexity of your system, it will go to a receiver, distribution box or volume control. These are in increasing order of difficulty and will require some extra steps.
6. Regretfully, if you plan on crossing some studs or firebreaks, you'll likely be drilling through the wall at an angle. Again, you'll be making a lot of holes to be patched up later.
7. Attach your wires to their proper destination. If you plan on having a wall-mounted volume control, it goes there first, then to the distribution box or receiver. Connect the speakers at this point also.
8. Pop the speaker into place, easy enough with the Speakercraft models. Direct the speakers to the proper listening space and go.
9. Obviously, you'll have to do this at least twice. Test each speaker before knocking out the next one. You'll thank yourself later.
Good luck, and have fun knowing you're accomplishing something truly by doing it yourself.
More information on in-ceiling speakers