And hang out here. Read the posts...plenty of tips.
You should also consider now how you're going to handle CS6. If you move to 5.5 now you'll get CS6 for free and save money in the process since 5 to 6 is more expensive than 5.5 to 6.
Another choice would be Creative Cloud at just $30/month for the first year with all the single edition apps you can create.