beat matching in pro tools who can lend a hand?

[infinitegalaxy]

lets keep this simple I'm attempting to use pro tools to put together some of my beats and it seems that if all the described editing functions preform as they should this should be an easy task. So I understand that pro tools has a function that allows you identify the beat so that samples can be inserted and snaped to the grid I have attempted this several times and I am aware that I should be able use the time expansion tool to match the sample with the bpm of the other track I try but to no avail I believe this problem stems from the short amount of time that I have used this program I'm used to using acid pro and adobe audition so any help would be great maybe a step by step walk through maybe?? Thank you all

newbie to pro tools
rg