If you have a good pair of scissors, mounting SU stamps isn't that difficult. Tips that I tell my customers is to make straight cuts, keep your scissor straight up and down. I haven't had a single customer ruin a stamp yet. To purchase SU stamps, you'll need to go through a demo (there are plenty here on SCS), but a good way to find one near you is to go to
www.stampinup.com and click on "find a demonstrator". Or search the forums and click on some blogs to see if you find a demo that way.
Welcome to stamping--it's a great hobby!