MyBB Community Forums

i have a facebook page i want to know how i attached facebook button on my site header like mybb community.
when anyone click on this so he redirect on my facebook page.
i want to know how i attached my tiwiter profile with my forum.
when anyone click on this so he redirect on my twiter page.

check this thread: http://community.mybb.com/thread-163110.html

please complete giude how to do this because i am new in programming