What recommended exercises and diets should one receive who has not worked out in a long time and wish to regain some muscle mass and tone the muscle?

Weights and protein. Your goals require weight training. Start light, shooting for twelve reps per set. As that gets easy, add weight and shoot for four to six reps per set to gain muscle. Keep your form honest - don't throw and jerk the heavy weight around as you'll just hurt yourself. This regimen requires one gram of protein daily per pound of body weight. Do cardio to keep your weight gain lean.
Start slow and build. Small changes lead to big results! So start with low impact exercise- walking, swimming, stretching, light weights - mix it up! Is most important - start 10-15 mins 3-4 days a week - and build up to 30-45 mins 3-4 days a week.... As far as diets- same rules - small changes - add healthy lean proteins, fresh veggies and some fruit, stick to complex carbohydrates - try to eat some lean protein every 3-4 hours a day to keep your metabolism going...Good luck! And congratulations on striving for good health!