You should have some base miles before beginning this plan. Ideally, you've been on the bike 8+ hours per week for at least 8 weeks. You can start this plan at any time during the season. You may notice more or less improvement depending on what you have done in the few months prior to starting this plan. Nonetheless, this plan will stress and improve all the physiological systems needed for success in cyclocross racing.
The plan also assumes that you are fresh and ready to start hard training. This is best achieved with a week off or easy week before you start the plan. This plan requires 10-12hrs per week with most of the longer rides on the weekend. It is suitable for a rider with a normal work schedule, but may require time on the trainer during the week due to limited daylight. This plan is not limited to any particular level of rider. The time commitment, however, may be a limiter and make it more appropriate for experienced or committed racers. Nonetheless, if this time commitment doesn't represent a large increase over your previous training volume, it may work for you. Finally, if you find yourself deeply fatigued at any point, you can simply take a few easy or rest days and then pick it back up.