Hi Lisa, you might want to start off using the gym first as buying dumbbell limits your workout options, and fact different workout will use different weight to optimise the workout, and one should always be 'increasing' weight to improve (I'm still talking about toning, not building big muscles just in case you are worried).

There are alot of insights to working out, which correct posture and correct movement is very important to 'hit the right spot' and make it less dangerous, and program designing is not easy too to attain what you want.

Many people can do away with trainers as they have read and see ALOT from magazines and video (certain things I still don't get it right even after 2-3 years into this). Certain workout you can see it, but when you do it you're not even sure if you do it right or wrong.