I'm looking to enter as a CAT 5 racer when the season starts up next year.
As of right now (mid September), should I be putting in base miles, or should I start doing the more technical stuff like intervals, hills, etc.? I figure I'll just do base miles until mid November/December.
It kinda depends were you are in your riding. You need to have a good amount of endurance so the base miles will give you that long distance riding ability. Hills are never a bad thing to do be doing so throw those in the mix.
Carbon Giant; my old steel racing frame is now a town bike, not that I use it much up here on the dirt roads ...
During the fall/winter it's important to build a base, including some hill work. But I'd wait on the speed work until about 8 weeks before your first race - no sense doing that now... Everyone's different...