I have a website that generates dynamic urls for all content.
It uses a function to show the content on index.php page and it's called by "action".
So, if the user wants to signup, there is a signup function calling it. If the user want's to browse downloads page, there is a downloads function calling it.
Something like this:
index.php?action=signup
index.php?action=downloads
index.php?action=news&type=type&id=id
In the last case are the news. The news are divided by type and ID, both numerics.
Type can be: article, update, etc.
My question is: HOW and WHAT must I do in order to transform it all on friendly URLs?
Presuming you are on an apache server, you will want to use a .htaccess file, and a method of using rules to rewrite URLs, not surprisingly called RewriteRule.
There's a ton of information through google if you search for .htaccess RewriteRule, but a great starting point is http://corz.org/serv/tricks/htaccess2.php.
You will essentially end up by putting a file called .htaccess in your public web files folder, with something like this:
Options +FollowSymlinks
RewriteEngine on
RewriteRule ^(?:/(.*)){1,3} index.php?action=$1&type=$2&id=$3 [R,NC]
Note: I've not tested the above, and it will differ depending on how you want your pretty link to look.