HI Corey
Once you have the box made and you have cut the top off ( with a slot cutter,band saw,router bit,etc.??) tape the box back up on 3 sides(with masking tape works well), chuck up a 1/4" solid carb. bit in the router table ,close the hinge and this is the height you want to use to set the bit height,then set the box on the table and move the fence so the bit will go into the space in the top and bottom,now for small hinges put some masking tape on the fence and mark it with the start and stop points you want the hinges to be on the box,then drop and plunge the bit into the box,then remove the tape and install the hinges.

If you have REAL small hinges (real thin ones) just use a smaller router bit,works great.
If you have a sq.end hinges just take a sharp knife and sq.out the corners.
Don't use a chisel, it will compress the wood in the corners and it time it will lift the hinges when it comes back in to place unless you use a REAL sharp chisel.
Just a note,,,,I use stop blocks on the fence inplace of the masking tape because it's dead on unlike the eye ball way (masking tape) and this is the last step in making a great box and the 2nd. thing someone always looks at.
B/4 you use this way find some scrap stock and tape it up and give it a test run you will like it because quick and easy and it looks great when your done.
Do it on two sides with the grain and across the grain this will give you the look of both.
Just a side NOTE***
This type of slot cutter works great for cutting the top off the box, 1/4" shank and use it without the bearing just with a small O.D. washer (SAE type or ANS) that's the same dia. as the lock nut. (2 or 3 of them)(the norm 1/2" O.D. nut,many router bits come with the small OD washer) and the router table fence.
http://www.mailwareweb.com/sommerfeld/item.asp?n=scb3a&d=75&b=1
Hope this helps
Bj