I have said to so many people.
You go into the gym and see these guys (and sometimes girls) and you can tell they are "NEW" to working out. They have on their new athletic shoes that look like they just jumped out of the box and are lost, they go to machines and just stare at them because. It's a RIOT! But, they do the thing that bugs me the most. They try and do the same things they see others who have been working out for years. I have been working out maybe benching pressing 200#'s and a guy half my size will come over and give me the "I challenge you " look. He will then try and do the same weight i'm doing and after 1 set he just leaves. He doesn't re-rack his weights, does not look my way, just jumps up and goes. Usually if you pay attention this is because he has hurt himself or took on more than he could handle.
I just wish that anyone that cannot afford a Professional Trainer at least for a few weeks join a gym that offers free trainer service so many times a year. You want to make sure you are doing the exercises correctly and with the correct motions. Don't go off of what you see someone else in the gym doing. Remember ask, or even better do RESEARCH. You can always go to places like www.mensfitness.com and www.menshealth.com. Both of those have programs you can join for dieting and exercise and they really do help. In this day and age where we use computers like our parents used TV, look up INFO just go to Google or yahoo or ask.com and type in bicep curls, back exercises, cardio training. You can find tons of info out there and you can even find programs to help you track your weight, your workout and lots of other things.
You have to also remember, patience and hard work is what it takes to get there, nothing is easy. Even if you start out small, go for a walk, a bike ride, do a small workout in your cube at work (yes it can be done) just start. It's good for you.