Its not exatly a how you need to learn css first.
just some basic css.
And then look at this link it will help
http://www.pokecommunity.com/misc.php?do=bbcode.
Also if you want to learn css and html this guys tutorial helped me.
http://youtube.jimmyr.com/tutorials/GwQMnpUsj8I.php
And thas about all i can help you with realy.