Lifting During Marathon Training

A week or so again, Megan asked if I wanted to come to a yoga sculpt class with her. I wanted to say yes, but realized that midway through my marathon training cycle probably wasn't the best time to start strength training. So I declined, but I really want to add it in to my routine.

For those of you who supplement your running with strength training, what sort of routine do you follow?

Are you able to maintain the same level of running when you're strength training?

When should I start?

I'm thinking I'll start after I'm semi recovered from Bemidji and hope that it's something I can maintain during regular training. In doing my daily glute strengthening exercises, I'm still noticing more weakness in one side than the other, so I'd like to do some targeted exercises to make them equal out.

Any other advice???