Depends on what it is. Check out http://www.liveaquaria.com">www.liveaquaria.com</a> and see what fish look good. You will usually see tank size requirements on the right size.
Put a list of all the fish you like up here, starting with the ones you want the most. Keep in mind some may need special requirements, like the jawfish needing a burrow, and you can't have more than 1 dwarf angel. From there it can be narrowed down to a suitable stocking list.
If you want to go check out a store, I believe All Things Aquatic is near you, and John won't steer you wrong on fish or coral selection, and you'll get to see the fish "in person" to see what they look like.