Before you buy it go to kenrockwell.com The info there will fill your mind for free.
I would also suggest geting a filter to work with the lights in the gym. For an easy to read on almost anything with photos go to kenrockwell.com
Ever try GIMP? it's free open source
I'd try this. Tripod, manual exposure, conyinuous release mode. then change the exposure times
The best camera you have is the one your carrying right now. If it's digital, takes tons of photos, 1 costs as much as 600.
Sometimes what you see is not what you get, and sometimes what you get is not what you see. The 1st photo is of course not nessy, It's just a cool cloud config at sunset. the 2nd is using a IR filter. Neither picture has been "photoshoped"