Create seo friendly URL's using mod_rewrite

I would like to use mod_rewrite to make search engine friendly from dynamic URL's. Our database was created using phprunner, using MySQL and PHP, however using mod_rewrite is complicated by utilising frontpage for ststic pages (causes problems with .htaccess). It is additionaly complicated (for a novice like me!) by the structure of the site, as it is a subdomain. Although my isp have advised me that the mod_rewrite module is active, I am unsure is this is correct. I have read a lot about this subject and understand it theory, but cannot quite get this to work. I am looking for: [login to view URL] to be changed to: [login to view URL] where category1, category2 and name are database fields. In addition to carrying out this project on one domain, I would like a guide as to how to apply this to my other subdomains, so I can implement this myself in future. Although this has been causing me some problems, I'm sure it would be a simple task for someone with the relevant experience.