Tularerunner - I've run about 90+ for the last 3 or 4 years - um, when I wasn't sick or injured or just loafing for a month each summer - and here are the rules I followed:
1) Build up the volume slowly. In my case, I spent 5-6 years going from no running in my 30s to higher volume in my 40s.
2) Run distance easy (I don't wear a watch as a way of avoiding the temptation to "compete" against previous times on any particular run), and save harder efforts for the 1 or 2 hard workouts you include each week.
3) Never run ANY workout harder than necessary to get the desired benefit - don't turn a tempo run into a time trial; run intervals at the pace you can handle that day and not at some fantasy pace that you wish you could manage; etc.
4) Stretch and do injury-prevention exercises after EVERY run.
Mostly, remember that volume is not equivalent to putting money in a bank account. It's not about banking miles. Like all training, it's about triggering adaptations. In the case of harder workouts, those adaptations occur during rest/recovery phase. In the case of volume, the adaptation occurs slowly, like a river carving out a valley, and requires patience and a long term mindset. Good luck!
As for my week, lots of miles and two great sessions with my son, Sean, who's trying to go from being a high school sophomore sprinter last spring to a junior 800 runner this coming season. Did 6 x 3 minutes with him on Monday, then 12 x 200 with him on Thursday. It was all at mile to 5K pace, so not hard for dad. But really, is there anything better than running with your kid when they really want to run with you?!
Hope everyone has a great week! See you in 2011!