a good pellet to start off with is anything from the jsb variety. air arms fields, jsb reds, jsb blues (which i use in my hw97kt), falcons, fx.
be warned though. falcons are very light and fly very close to the limit. it'd be worth trying them over a chrono. my 97 does 10.9 with jsb's, but 11.5 with falcons. a big difference, so its definatley worth shooting a string over the chrono.
i find the falcons are great out to 35 yards, but can be a bit irratic in the wind. its because they're so light.
most guns shoot well with jsb made pellets so they're always a good place to start. acc