goobster got you covered. As far as exploring Hubski goes, I can tell you that unless you are going to click "inactivate account" there's nothing you'll regret (and even that is reversible as far as I know). Go to your profile, explore the settings, don't be afraid to ask if you are confused and generally get to know the place. Seriously, go around and click stuff to see how it works.
Actually, I can link you to some of the more 'advanced' features I found on Hubski:
It's a really cool site to explore and I can wholeheartedly recommend doing it. If you'll find a bug make a comment (or a post later on) about it and tag it as #bugski. mk is the site admin/owner/overlord so you might want to shout-out to him. How you make shout-outs? Click the 'markup tips' above every text field where you write your comments.
What kind of stuff would you like to post? I'm just curious.