@youramericanlover held hands with me at the NYD Madison Cross a few years back, so he has racing history.
If I was doing an 8 week plan, I'd split it into two four-week blocks and focus on three main areas:
- aerobic fitness
- vo2 max
Depending on how much time you had, I'd do 3 fitness sessions a week and 1 skills session, plus a longer ride if you have time.
In the first block I'd focus on aerobic fitness, so 10/15/20 minute efforts with recovery between them. Start short and build up to 2x20 minutes in the third week. Then have an easy week.
The second block will have more focus on vo2 max, so 2-3 minutes at the highest intensity you can hold, short recovery and repeat up to 5 times. Two of those a week, plus one aerobic session.
On the skills side, and remember you can't throw fitness at a skills problem, I'd focus on transitions on and off the bike, slow speed cornering and faster cornering.