Gearing up for a 5K race

I am planning to run in a 5K race in May that is part of a larger set of races that include a marathon, half marathon, 10K, 1 mile and kids run. A friend of mine who has been running for a couple of years will be joining me. I'm confident that I'll be able to run a credible pace for 5K by then but I do need to work on both speed and endurance. I'm going to try to run a 5K course this weekend as a way of training for the upcoming race. I use Google Earth, Gmaps and MapMyRun to plan my routes. They are all very accurate (to the inch) so you can plan ahead or track where you ran against your elapsed time to calculate your pace.