Here's just some tips from me and Rach
Be sure to do all the servicing on your bike when you get it to keep it lasting longer.
1. loctite all major bolts (i.e. engine mounts, handlebars, etc)
2. Drain the shipping oil from the engine and change it with some mineral oil (use Castrol Activ 4T)
3. oil chain and air filter (proper air filter oil only for the filter)
4. Run the engine in properly (Just ride a bit tamer for the first tank or two of gas)
Here is some threads you might find useful.
Run it in hard not tame! Unless you plan to ride like a sissy!
How To: Run in a new engine. Run it HARD
Nitrous 150 build.... how to get the most out an ebay junker
Achtung Noobs! : Your New Pitbike and You... set up tips
How to set Valve clearances on horizontal engines.
Performance upgrades guidelines: Stage I-III