Other than cleaning the surface well, is there anything that should be done to prevent any problems with placing stripes/decals? Also, any tips on keeping them looking new (and stopping them from peeling at the edges) once they are actually on the car?
Get a bottle mixed with soap and water, drench the surface then place the stickers into place. This gives you room to fix a mistake by letting you move the sticker were it needs to be. Push all the air bubbles out then let it sit in the sun the the water can evaporate into nowhere.
one table spoon Dawn-1 gal water.
I like to use a small rubber squeegee instead of the little plastic scrapper. www.graphic-express.com may have instructions on their website.
And if you do screw up...it's ok..that's how you learn.
Try a small one 1st. Get the hang of it and then you can review your mistakes(if any). I had to learn from my mistakes...and I got better at it.
Go for it.