A Power Meter And A Good Book
A power meter can significantly improve the quality of your training time. PowerTap ($1000+) measures power at the rear hub, while the new Garmin Vector ($1,499.99) uses a pedal-based power system—both helpful if you own more than one bike, the latter if you want to swap wheels. Set aside $25 for Training and Racing with a Power Meter by Hunter Allen and Andrew Coggan, Ph.D.—the best read to get the most out of this investment.
Tip: Shop through a local coach or dealer for the best price. Fascatcoaching.com provides bike set-up and a free month of power-based coaching.