Coming from someone who has administered over a forum with over 500,000 members in the past (a gaming website no less, imagine all the needy children!) I'd say that this site has provided more than enough information for any geocaching "newbie" or enthusiast. There is no customized welcome message but for a site like this that's almost impossible to do.
As many before me have said the FAQs provide a wealth of information and the community itself is more than willing to answer questions or provide tips/information to any newcomers.