DL some bots and hop in the chair just to practice dropping everything and learing the build orders of everything, take special note to memorize the hotkeys and try to streamline moving as much as possible. After that, go to the fronteersman strat forum on the NS site, or there are also tonnes of com stratigy articles around, pretty much every NS website has one hidden away somewhere. Read one or two until you feel like you really have the hang of the stratigy and build orders involved, then all that is left is to get experiance. Hop in the chair and fudge around, make sure you are applying your build orders and keep tabs on everything so you always know what nodes you have, you need, and where you are in terms of teching, and then on top of that make sure you respond to EVERY med and ammo request and drop a node ASAP on EVERY order request (The requests pop up on the lower left hand side of your screen, you can either press your jump key or click on the request icons to zoom to the current request) after you have mastered all that to the point where no one complains, get on the ball and follow your marines around medding anyone with low health (at the same time as everything else of course) and dropping RTs and/or structures peemptively, and before you know it, you will be a GREAT COMM!