I've met several middle school coaches, or people who are interested in becoming middle school coaches for cross country and track. Most have little experience with the sport and they are either teachers looking to give their kids an extra curricular opportunity or a parent with a child who is interested in the sport. Having to start basically from scratch can be a daunting task, especially if you don't even know where to begin. Here will be a short guide for middle school coaches to build a successful and lasting program.
First, you need to talk to the administration and find out what you can and can't do. Each school has different rules and working with those rules will help establish a routine that your team can get use to. Also find out what type of budget your team will be allowed to work with. Regardless of what your budget is, I would recommend you planning on some sort of fundraiser. I don't think I've ever heard a coach say "my team just has too much money!"
Figure out who will be your support staff. Will you be able to have assistant coaches? Will there be any parents who can offer their time to help you? Having people help you organize practices and gather the team on meet days can help save a substantial amount of time. This allows you to get so much more accomplished during a regular practice.
Next you need to figure out what your training philosophy will be? Keep in mind that many of your athletes at this age will be first entering the sport, and potentially sports in general. You will definitely need to consider the developmental aspect of training younger athletes. One mistake I believe coaches make is thinking that youth athletes shouldn't be exposed to all types of training, and it should be overly simplistic. You should teach fundamentals such as form; introduce speedwork and allow the kids to work on their efficiency; and also allow the kids to get stronger just doing some basic strength training exercises.
Lastly you need to figure out what will be the unique aspect of your team that will keep the kids interested and will retain them in the sport for years to come, possibly even for years to come. What can you offer the athletes that will leave a lasting memory of the sport and perk their interest? Consider this as well when you are building your team!
I will leave you with a short little sample training week for middle school runners. This is just a guide. You need to figure out what is best for your teams!
Monday- 3-4x 800 at moderate intensity with 3-4 minutes recovery between repetitions based on ability.
Tuesday- 30x 100m strides
Wednesday- Off or 2-3 miles easy
Thursday- 6-8x 400 @ goal race pace for weekend meet. 1-2 minute recovery depending on ability.
Friday- Easy jogging, stretching, and strides
Saturday- Meet
Also, add in some pushups, crunches, lunges, etc. a few times for a few minutes a week. Remember, these kids are in the developmental stage. Just running mileage might make some great joggers, but not racers in middle school.