Here is a link to a site that shows you how to cut the nails and has lots of pictures.
http://www.vetmed.wsu.edu/clientED/dog_nails.asp
I use the cat scissor style nail clippers, they work great for little dogs who have little nails. If you are afraid to clip the nails, just do a tiny bit each time and don't go past the curve or you will cut into the quick. If she hasn't had her nails cut for awhile then the quick has probably grown out to the end of her nail. Which means you will have to cut a tiny bit each week which will cause the quick to recede (sp?). Also have the quik stop ready incase you do cut the quick and she starts to bleed.
Once you get the hang of it, it comes to be very easy to do and you will fill confident doing it.
I groom all my dogs myself so I am the one cutting all their nails. I have been doing it for years so I can cut their nails without worrying about hurting them. In fact if I do take them to the groomers I won't let them cut their nails as some groomers aren't very good at it and have cut the quick.