Trying to play a Malkavian character is a very tricky thing. Portraying someone whose mindset is extremely different from your own presents a number of problems. Fortunately, we're here to help. And remember: have a little fun while you're at it.
You may wish to take a look at the Malkavian Nature page or the Storytelling Malkavians page.
Some possible derangements for your character.
Some Malkavian Templates. Also, a word from Daniel Greenberg about why the templates in the Clanbook don't have Derangements.
From Visitant, a list of Merits and Flaws from the White Wolf literature which are particularly applicable to Malkavians.
An ASCII V:TM Character Sheet. Personally, I recommend the PDF version.
Is it viable to play a Malkavian in a story, where the malk's random desires can end up pulling the group completely off track?
Recuiting for the Sabbat (Doesn't really belong here, but I can't think of anywhere else it would fit better.)