First, estimate when you expect to be ready for your first 50K. This can be determined in two ways. Decide what type training program you intend to us and see when it will have you ready. With the training plan outlined in the last post (30 weeks starting with one hour long weekend runs), look ahead 30 weeks. If you start the plan running 3 hours, then you will be ready in 15 weeks. Next, see what races you can find about the time you will reach the 5 hour training runs. The second way is to find a race you want to run modify your training program to peak about three weeks before the race. For your first ultra I would recommend the first technique.
Next, selecting the right race. Ultrarunner.com has a great calendar of most of the ultras in the US. Look at the upcoming races in you area. Ultrasignup.com is another place to look for races. You can also check the run calenders on your local running clubs and running stores web sites. You might also want to try a Google search for "trail races in your city or state." This will also turn up more local races that may not be listed on the major calendars. I recommend trail races in your area for your first ultra just because it is a lot easier to go to a race close to home, and a lot less expensive.
One good race in North Alabama is “The Dizzy Fifties.” (This happens to have been my first 50K.) The course is three 10 mile laps in the form of a figure eight. Each Lap consists of a flat, six mile loop and a four mile loop with one large hill. In the three lap 50K you will come through the start/finish area, which also is the aid station, six times. Your stuff is never very far away. A loop course allows you to put any and everything you might need during the race at one location. This makes planning simple.
If the 50K you select allows drop bags you will need to decide if you will really want to fool with bags and what to put in them. Usually it is easier to carry what you think you will need and not waste time with drop bag on a 50K. Another great first 50K would be the race I am putting on in Birmingham, Alabama on May 5th. It is the “Run For Kids Challenge,” a fundraiser for Camp Smile-A-Mile, Alabama's camp for kids with cancer. Take a look at the website, runforkidschallenge.com. The course is a 3.2 (approximately) mile loop on a beginner bike trail around the swimming and canoeing lake at Oak Mountain State Park near Birmingham. The trail has gentle, rolling hills and is very runnable.
Next I will talk about tapering and recovery.