2 Do check the changing rooms. If the floor is dirty and rarely cleaned, you might end up with a first-class case of athlete's foot to go with your new muscles.
3 Do warm up before exercising and warm down afterwards. There should be enough room in the gym for you to do this.
4 Do ensure the membership includes a regularly updated work programme designed for what you want to do. There is little point working on strengthening your upper body when all you want is to be able to run for the bus without collapsing in a heap.
5 Don't let the instructors rush you into signing up for a massive membership fee. Shop around, most gyms should give you a free introduction to their facilities before you have to join.
6 Don't dash straight to the heaviest weights. Take things slowly. It would be silly to pull a muscle or let frustration turn you back into a couch potato after only a few sessions.
7 Don't try to compete with the other members. They may be able to benchpress 160lb with their little finger but they may also have been training every day for the last 10 years.
8 Don't be afraid to ask if the instructors have proper qualifications (from BAWLA for example) and make sure they show you the correct technique for each machine, not just how they work.