How do I set up my domain?

-Alright I have a domain I want to point to my tumblr account (So I can use the tumblr as a home page of sorts) but I also have forums on that same domain/server that I would like to keep using.

I also want to keep this all on one domain.



On tumblr.com they explain how to point the domain towards your blog using an "A" Record so I did that and everything worked, but the forums.



What would be the best way to set things up so they both work?