If you are looking for fancy options, look into Ekahau. They have several moderately priced packages for planning a wireless network. There is all sorts of surveying and auditing options. It's also very well supported so new hardware shows up in the tool pretty quickly. So you can import a map, draw your walls (or if you have a CAD drawing, it will draw walls for you), then select what model Extreme AP you are using, then select what you want to accomplish (data, wireless voice, etc) and then hit autoplan and let it crank out a placement map for you.
There is definitely a learning curve to the product, but it's a nice investment if you are going to be doing more areas or other buildings.
Oh, and you can export your plan in "Cisco format" and then import that zip file to Extreme so you don't have to go and re-draw everything. Just match up your generic named AP's with your real Extreme hardware in XMC and you are done.