Thread post look [borders, backgrounds etc]

I've recently created a forum, and I've figured out how to do a lot, but can't for the life of me work out how to put borders, background colours and change the look of posts we submit.

It's just looks plain white with a single vertical thin black line between posts and the profile box.

I would really like to also have spacing between where the text begins in everyone's posts. Is there a way to do this?

Thank you for anyone able to help.

Natalie.

Hello,

Please provide a link to your forum.

http://simrepublic-anguilla.freeforums.org.cn/forum.htm

Sorry, I should have included that first.

I also want to change the post backround and the forum border backround. How to do it ?

Maybe!
I need to use phpbb3, because I tryed it, and I was able to change it.
But it changes my font look on forum ! How to change font on forum is a silly question, isnt it ? I do not know how yet...