Here are a collection of links I've found helpful in my search for races and gear. Hope they help you too!
Rock 'n' Roll Marathon Series - You want to do a half marathon or marathon but you don't want the pressure of only serious runners. These races are fun and have a time limit long enough that you could walk the course (at least the half anyways). Bands along the way and at the end make it a great way to take the pressure off that first long race.
B.A Events - For those based near Boston you'll find a fun run with post race BBQ and free beer until the kegs run dry. If that's not encouragement to run fast I'm not sure what is.
Run Keeper - Smart phone app who's GPS is pretty accurate and lets you track our running, cycling, rowing and a boat load (sorry about the pun there) of other healthy activities. Connect with friends to form a "street team" and track your progress challenging and encouraging each other along the way. They also have some great training programs.
If you're new to running I'm going to tell you three things. 1) Go to the doctor to make sure you're healthy enough to do whatever distance you're going to do. 2) Don't go crazy at first. You can't run 15 miles a week right after getting off the couch. 3) Go to a running store and get fitted for some running shoes. The proper fitting shoes will save your whole body a lot of pain. In the Boston area I would recommend Marathon Sports or Greater Boston Running Company. Not in the Boston area? Click on the Greater Boston link and find a store in their network.