welcome mumnson. well said ricky. mumnson, its not a race bud, everything takes time. the more time you put in now getting knowledge, the more it will help you know end in the future and to be honest you are in the best place on here to find out. dont be shy to ask questions and more importantly have a nose through old posts.great info about! all the best mate.  

Thanks guys for your replies. I have been doing alot of reading on this forum and the internet and reading some books I bought on this subject and asking lots of questions to the ones in the know at our local gym but there are  still got loads of things I want to understand.
To explain our situation my eldest son is 16 and wanted to do weights. He has a back problem so I want him to be safe and that's why I want to understand everything. I joined the gym with him and his Dad but for some reason he prefers the times I can go. I'm no body builder but am serious at improving and supporting him as a training buddy as he does his workouts. We have been going for about 2 mths now and in that time he has now doubled and in some cases trebled his initial lifts. We use a lot of free weights and to keep control we have also done the seated version of a lot of the exercises. He's had no problem so far with his back (he fractured it playing rugby and was in a back brace until about 10 weeks ago.) so we will be taking it easy.

oh right. well what your doing seems to be right. just take it nice and steady. dont let him push to hard to soon. if he gets any pain or twinges tell him to leave off. its better to start slow and get a strong core than to aggrivate the old injury and set him back 6 months. dont worry about asking anything no matter how silly or stupid you might think it is. theres always someone to help on here. we all had to start somewhere

Thanks!! Gunna make this my new routine

thanks as I just train at home and dont really know about sets and reps, I just usually train until I cant do anymore