All about the URLs of your blogs for newbies (permalinks)

A reminder for some bloggers or a source of information for newbies, here is all you have always wanted to know about Wordpress and the URLs of your blog:

http://codex.wordpress.org/Using_Permalinks

 

Speaking of permalinks, what structure do you use? I use the /postname/ structure

 

I do use the /postname/ structure too

But I will maybe switch to /category/postname/ which is an interesting structure too

 

Some of my friends use the /index.php/postname/ structure. Is there something special in it?

 

Thanks Lastbutnotleast, after advice here not long ago, possibly from yourself and others i use /category/postname/.