S!+ and welcome!
You can get into big trouble if you go too fast and muck it up!
Install PL B4 HA(follow Cas141's patch order). Visit the newbie pages listed in my sig for valuable and possibly critical info.
von Tom's Campaign Manager (CM) is indespensable for further small patches you may want to install (like invisible cockpit etc) and for restoring killed or maimed pilots and for removing patches that don't have an uninstall option etc etc.
Squad Ed lists the dates of the advent of each airdrome and plane type used by each squadron (usefull if you want to campaign with a certain plane type etc).
Jeez,I can't go on,I'd never get finished listing all the cool stuff available for RB