Your routine is pretty bad. The point is to make your body into a muscle building machine, and the way to do that is with heavy compound lifts that hit the largest muscles in the body, so your body is like "whoa I better get in muscle building mode." Right now you are hitting only the smaller muscles, so you aren't making muscle building a priority for your body. Your body isn't going put all that much into muscle building just because you lifted 45 pounds with your biceps, but if you were to lift 300 pounds off the floor then it's going to start taking stuff seriously. You are also working the muscles you work too frequently. It probably doesn;t matter since they are small muscles, but in my opinion twice a week is better.
You want to base your routine around these lifts: squat, deadlift, pull up, row, bench press, military press.
You have the right idea with your diet. Are you a vegetarian? Protein is important, but so are carbohydrates and fats. I eat 1:1:1 ratio of carbs to protein to fats. Healthy fats of course: salmon, nuts, olive oil, etc. The thing is, you have to eat more calories than your body uses in a day, so that your body can build muscle with the extra calories. If your body needs 3000 calories to do important things with, then if you only ate 2000 calories that day, your body is going to use those calories for more important things than building muscle, no matter how much protein you eat. It'll probably be pretty hard to get the amount of calories you need in 3 meals. I'd shoot for five medium sized meals. People will tell you a fist sized meal every two hours. Whatever, you have to figure out how much food you need for yourself.
A multivitamin is a good idea, from what I hear. I take one. The thing about supplements is that if you are doing everything right -eating, training, resting - then they might help you add a couple more pounds of muscle a year, or a little less fat, or something, but they aren't going to be the difference between not gaining and gaining. If you are doing something wrong they won't fix it. A whey shake post workout is a good idea. Although, I'm sure I could find something somewhere saying it isn't. If you can't afford creatine then don't worry about it. It certainly isn't required in order to gain muscle. You know? Maybe it'll help gain 2% more muscle than you would without it. Definitely not neccessary. There's not really any reason to take caffeine before your workout at this stage.
Here is a sample routine:
Monday:
Squats 3 x 8
Straight Leg Deadlift 3 x 8
Tuesday:
Bench Press 3 x 8
Pull Ups 3 x 8
Friday:
Deadlift 5 x 1
Front Squat 3 x 8
Good Morning 3 x 8
Saturday:
Military Press 3 x 8
Bent Over Row 3 x 8
That's just to give you an idea of what a good routine looks like, in my opinion. You can add in some isolation stuff, or direct arm work, or whatever.
http://exrx.net/Lists/Directory.html has videos of all exercises.
Also, on deadlifts, squats, good mornings, bent rows, you want to keep your back slightly arched, never rounded. Try and get someone to teach you these lifts.