Brand new to tri... advice welcome

I'm brand new to Beginner Triathlete, and am here because I've heard wonderful things!  My goal is to complete my first tri next season, probably in June or July.  I'm still debating which race to register for.  I live in San Francisco, so I know I have many possibilities.  My brother has been a triathlete for years, and I'm tired of watching him.  I want to join him now!

I am looking for any tips, advice, words of wisdom, things I should look out for etc.  Anything is welcome!  Here's a little info on me if it will help.  I'm an avid female runner in my early 30's.  I've completed multiple half -marathons and one marathon over the past couple years.  I love running, but am ready for what's next!  I have a decent road bike and though I know how to swim I'm taking lessons for improving my technique this winter.  I haven't swam or cycled regularly since I was a kid.  

On a completely different note, for two days now I've been trying to upload a photo to my profile, and the site keeps telling me there's an error.  Any technical help or pointing me in the right direction with that would be great!

Thanks a milion