i would also recommend a GPR stabilizer that will be the first mod i do on any bike i buy. to me the stiffer steering and the on the fly adjustment is an awsome part of this mod, imo it also makes the bike a bit safer and more controlable and comfotable.
the next step might be bmc air filter, 520 chain and sprocket kit, with gearing changed -1 front +2 rear.
if your new to riding don't worry about performance mods yet, your first mods should be investing in are yourself... all the saftey equipment, mfs course, make sure you have good tires. if the tires are original (4 years old) look into some new shoes.