Categories and Permalinks

Hello,
I am a newbie to WP, but starting to get my head around things. One thing I wanted to achieve was to have a seperate page for each main category. To achieve this I copied the index.php file and renamed to (as an example) About.php and services.php. I then added code so that each of the pages would only display entries for that category (via cat id). I acheived this in part by reading http://wordpress.org/support/4/7382 and the wiki.
I have however encounted a problem, and the same problem noted here http://wordpress.org/support/4/6721 where my permalinks point to the index page rather than the category page they are related to.
Within the discussion (6721), it mentioned that mod rewrite would have to be changed. Now I dont know what mod rewrite is, not a clue. Can anyone help me? Indeed, I have also found a recent thread, that notes you dont have to change mod rewrite, but unfortunately it went over my head. A little guidance would be greatly appreciated.
Regards,
Lee