Help Please!

I’ve recently become VP admin of a society at a university and part of my job is to send a weekly email to all of our society members.
The problem is, I thought, that I knew how to do basic html format, and the first time I did it… It worked! I used; <> with various b’s and u’s and what not.
The problem is that for the last 2 weeks. It HASNT worked. The weekly email has gone out with <>'s and letters all over the show. Can SOMEBODY PLEASE tell me HOW to make text bold, underlined and what not? It’s fustrating me. The majority of our reciepients use hotmail, does this matter?

What are you using to send your mail? Webmail, a mail client, or one of the Announcement/Discussion lists?