Any good tutorials

Hey guys i just got this program and it seems to be great but i want to chance a few things like in the grid i played around with it and i cant seem to find the file that lets me change it to be more than 3 products wide. i am just looking for a tutorial for this or some where to tell me exactly what file will edit what part. thank you

i think your talking about  
templates-->categories-->productsInGrid.ascx

but you will also need to start editing the .css files to increase the width of the page for 3 products to fit