Drainage is way important, I have a MXtrack that is a mile and1/2 on 8 acres, I put all kinds of time into making it perfect and it was great until it rain hard a few times, in some spots it was like a pond, all the berms,jumps,and whoops, block water. I had to do alot of work puting drainage tile, it works great now, and make it so it is easy to mow, I have my whoops 4 feet apart sounds like alot but my mower fits right in there, and so does the bucket on my skid loader. weads will be a prob so get your self a small little wead sprayer one that you can tow around, they are about $200 cheaper if you find one used. I live in Iowa and I'm sure you get alot of rain like we do here. and have some grass sead for those times that you tear into the ground. this may sound crazy but 4 wheelers riding around the track eliminates ruts and they build the burms nice. as far as building it, draw something on paper and study the lay out of the land, have your longer doubles going up hill, as well as table tops, rythemsections are a blast cause you have to time them just right to go fast, and that means slowing down to get them right. anyway good luck.