Doing a fresh install on macbook & want to make sure I will have access to old files

[leglez]

I have a Macbook Pro 13" Mid 2010 and I am getting ready to upgrade from OSX 10.7.5 to OSX Mountain Lion and I am wanting to do a fresh install. I am wanting to backup all of my data before hand though that way if I need something I can still access it. I am currently backing up to time machine. Will I be able to access it from a new user account on Mountain Lion or will it lock me out since it is a new account? Thanks