First off there are 2 basic models of GoPro
1) The GoPro wide (non HD) referred to as [helmet, motor, whatever...] hero wide
2) The GoPro HD same as above except HD
So first off you have to decide wether you want a regular Gopro or a HD one, it's about 100$ or more difference i believe.
They're both great cameras but the quality of the HD is mindblowing !
then you have several types of packages for both the HD and the regular gopro.
lets say you order the helmethero package, then you receive the GoPro camera (HD or non HD, depending on what you ordered), and a bunch of straps and mounts to attach it to you helmet.
another package; the motorsports hero doesn't come with the helmet mounts but instead comes with a suction cup to mount the cam on your car or bike.
surf hero is the same except it comes with a large sticky mount for your surfboard...
then there's also the "naked" package; this is just the camera with 1 or 2 regular mounts i believe...
What i'd suggest you get; get the Helmethero, preferably HD if you have the money...
(also if you order your camera, and it's non HD; order rechargeable NimH aaa batteries as well + a 2gig SD card.
If you order the HD hero, the battery is included but you still need an SD card: i advice a kingston 16gig class 4 SD card (other brands might work as well but kingston is tested and adviced by gopro) )