Hello

A friend of mine is trying to put together a four day workout plan mixing cardio and weights and focusing on the lower body. She doesn't want to bulk up either. Just trim up i think. I was wondering if someone here could help me put together a work out for her ...general guidelines and more specifics if possible. which machines, low/high reps, what kind of cardio.. anything would be very helpful. Ideas anyone? Much appreciated.

putting together a workout routine is pretty tough without knowing the person ... male/female, age, weight, goal weight, current training program, etc.

I can say, however, if you are looking to train the legs, that i would focus on biking for your cardio. Maybe 3 days on the bike and 2 running for 30 minutes/session (more if you have the time).

If you don't want to build bulk then I would be doing high reps (12-20) for everything.
Squats are always the basis for all leg routines, so that is crucial ... and there are plenty of different machines to help you there to get proper form ... do 2 different types of squats each routine.
Lunges are always good ... leg extensions are bad for the knees, but many people do them anyway. leg curls ... calve extensions/raises