I would recommend you join a gym. They can teach you proper lifting technique and tell you abou nutrition and stuff like that.
The weights you have now will do in the beginning, but eventually you won't get stronger & bigger if you keep using your 40lbs weights because your body will get used to the resistance.
That's the key to getting stronger. You will have to continue giving your body a resistance it's not used to (overload).
I started out like you. Training at home with dumbbells. Getting little result, because I didn't really know what the hell I was doing. But now I train at the gym 3 times a week. I wish I had started in the gym in the first place. It would have saved me a lot of time.
Plus the gym is a great place to meet new people.
BTW, if you really want to train at home, use a weight that allows you to do 8 to 12 repetitions maximum if you want hypertrophy (muscle growth). If you do more you reps you will be training for muscle endurance. If you do less, like 4 or 6 reps you'll be training for power. Which will make you stronger, but you're muscle won't look as good.
On other thing that's very important. I don't know how many times a week you plan to exercise, but make at least every other day a rest day. You're body will need time to recover from a heavy training. If you train too much you'll actually get weaker instead of stronger.
Good luck man!
Peeaayempee
BTW. I'm doing my NSCA Personal Trainer exam in november so if anybody has any fitness related questions, ask me. It'll be a nice practice for me.
