Okay, so it's been a few years since you lifted. No biggie. Here are a few pointers:
- Start light. Let your muscles remember the movements.
- For general toning, do three sets for each exercise.
- Do 10-12 reps per set.
- The proper weight is when you struggle to get to the 12th rep. If you can't reach 12, you are using too much weight. If you blow through 12 reps, there is not enough weight.
Machines are good, but don't shy away from free weights, especially dumbbells. They allow you to use muscles independently, thus causing fewer imbalances.
As far as stretching goes, check out Sport Stretch: 311 Stretches for 41 Sports by Michael J. Alter. This great book details how to stretch and explains sets and duration of each stretch.
I hope this helps. Let me know, Jessie!