Do 2-3 days a week to start and aim for 4-5/week
Usually my routine is chest, biceps and cardio on Mondays - (3 sets of 8-12 reps for each of these - raised leg pushups, dumbell bicep curls, incline bench press, isolation bicep curls, standard bench press, hammer curls and finishing off with standard pushups). Follow with cardio - either running or bicycle. This shouldn't take you more than 1 hour a day. You should be able to get the weights done in 30-40mins.
Tuesday - Triceps and Back (3 sets of 8-12 for each again - lat pull downs, tricep kickbacks, dumbell row, tricep dips, shrugs, narrow grip pull ups and finishing off with weighted rows). I dont do dead lifts as they tend to do more harm than good. Cardio again afterwards.
Wed - Rest day
Thurs - Shoulders and abs - (3 sets of 8-12 for front and lateral dumbell raises, shoulder press, crunches and 3 sets of 8-12 30s planks. Cardio afterwards
Friday - Leg day - squats, hamstring raises, calf raises etc etc. This is the one that usually knackers me out so Im out of the gym in 40 mins as I dont do cardio on this day.
Slender tone works but only really for shaping. If you have a layer of fat over the abs, it won't make any visual difference.
In terms of contracts, Puregym do rolling 1 month contracts and they can be moved to another site, for example if you move to another part of the country. Mostly, I prefer to go to the backstreet gyms which are cash for 1 month and end of.