Trying to learn guitar?

Ok so all my life I wanted to learn to play guitar. I'm in my late 30's ( so I know I'll never be a lead player in some rock band) but I would like to be able to play some of the riffs of my favorite songs.

Anyway I just purchased a Epiphone LP 100, and also ordered me a copy of RockSmith for my xbox. But before Rocksmith comes in the mail I decided to try and play some tabs I found online. First problem I have found is I can't pick out the correct fret on the neck, to put it another way I'm always counting the frets.

Here's my question would it be ok to take a lable maker and number the frets or would that be a bad way to learn? In other words would it be developing a bad habit?