^^^ agree with everything above. 1 piece and leather is best, but 2 piece leather might be a little more practical/comfortable if you'll be riding around city and using for everyday use, at least then you can drop jacket when you get to where youre going.
as for helmet... make sure it fits, nice and snug. i have heard that injection molded plastic shells arent the best in a crash, people generally steer towards fiberglass/other composite lids. that being said i am partial to shoei, they have always made something that fits me.
boots, if they bend sideways they're no good. pick them up and bend them, see if they will move in any direction you wouldnt want your ankle going. as much as i dont like their shop... riders choice... daytona boots are hands down the best money can buy. but they are damn pricey.
gloves, make sure they're gauntlets. then little things, like pinky/ring finger sewn together, extra reinforcement in areas.... are all other things to look for. look at "five" brand gloves. really nice stuff. and im sure that many here would agree.