ride, ride, ride, rest and repeat
are you training for just ONE race or racing in general over the entire season. you might as well do more than one if you are going to be training.
anyway, there is just too much to tell you, basically, go buy the Mountain Bikers Training Bible or any other cycling training book, that would be the best way to go.
VERY Basic Overview
3 different types of stages or phases
1 - Base - long easy to moderate rides 8-12 weeks at least (more base is better), building up time on the bike, try to put in more time each week.
2 - Build - less time, but more intensity, intervals, pace rides, getting specific (start doing races) - again 8 - 12 weeks depending on schedule for your season
3 - Peak - even less time on the bike, but high race like intensity in short periods of time. 2 - 4 weeks depending on schedule for season - this is when you want your important race to fall in.
In all Stages, take a rest week every 4th week. Ride at least 4 days a week, but always take at least 1 day of rest each week.
Again, those are the basics. Don't go too hard to early in the season.
BTW, I like a VERY hard effort about 72 hours before a big race and a very easy pre ride of the race course the day before if possible (1 hr max), lots of pasta, water and sleep.
Good luck.