Networking comes later, but at first get to know other more senior umpires. If you can pick one that you want to be like because of his mechanics/rules knowledge, game management etc. and make him your mentor. Always show up to your assignments 30-45 minutes early and get a pre-game with your partner. If you really want to impress people and get your name out there, call your partner(s) a day or so before your games to talk about plate/ base assignments, where to meet and color options. This will let them know you are thinking ahead and you mean business. Nothing impresses me more then a junior umpire contacting me before I contact them. I agree with everyone about looking the part. Dressing like a real umpire makes you feel like one and others (coaches) will believe you are. At camps get numbers and emails of other umpires in your area. Good umpires will help you get games and give you a shot if they see you are driven.