Hello there...
I'd say the biggest pitfall you face is starting an implementation without knowing what you want to achieve.
SharePoint is a brilliant product, and you can do LOTS of things with it. But its flexibility means that you can go down all sorts of roads that may be irrelevant to you.
What are you looking for? Collaboration, document management, a new intranet, workflow, records management.... ??? My advice would be to work out what you want to achieve first.
Also, be aware that if you just want to gain some initial familiarity with the technology, there is plenty that you can do with Windows SharePoint Services 3.0, which comes free with win server 2003/2008.
Finally, I can warmly recommend 'SharePoint 2007 - Best Practices' by Bill English etc (MS Press) - this covers a lot of the kind of stuff that it pays to think about, with some great recommendations. Many of these recommendations could be included as part of your initial setup.
Good luck with the project!
Cheers, John