If you don't have a power meter, then heart rate as it relates to speed/time for a given route is a better measure of performance than speed alone. If you don't like Friel's book, there are many other resources available; you might like Chappel's book on base training better. My best advice is to work backwards from your A races/events. You want to work on specific training as you near your A event and taper so you're fresh and ready. You can also use the ATP scheduler in Training Peaks if you're using this online program.

Personally, I'm following a schedule on page 174 in Training and Racing with a Power Meter, 2nd edition. My goals, and strengths and weaknesses nearly match the Bob Rider character Allen and Coggan use as an example - how fortuitous! However, I use a power meter. Even so, I've worked backwards from my A races in July in creating a training schedule.