I am no expert, but I will offer what I can.
DEFINATELY see a personal trainer for awhile, if you haven't had much experience in the gym. You need to know the correct technique for the exercises you will be doing, or you could injure yourself.
Make sure you warm up before a workout. Run on the spot, do jumping jacks, whatever it takes to get the blood flowing. Then,
stretch before your workout, concentrating on the muscles you intend to work that day. When you are done your workout,
stretch again, and again concentrate on what you have worked. I have done a study in a kinesiology class that involved exhausting a pair of muscles, and then stretching one often over the next few days, while ignoring the other (was the wrist extensors, the muscles on the top of your forearm). The forearm that was stretched healed faster than the other, and was ready to be worked out again sooner.
Once you've been shown exercises and are familiar with the equipment, get a good routing set up. The trainer can help you with this. Depending on how many times a week you will be going to the gym, you will need up to split up your muscles groups to different days.
For example, if you're training 3 times a week:
monday: chest, abs
tuesday: rest
wednesday: arms, legs
thursday: rest
friday: back, shoulders, abs
saturday: rest
sunday: rest
Don't work a muscle group again until it isn't sore anymore. They need time to heal and rebuild.
As for diet, consistency is the key. Eating a good breakfast is the most important thing you can do. Eating a good post-workout meal is the second most important. Do your whey protein shake right after the workout, not before. Eat again a few hours after the workout.
The idea, in my opinion, is to make your body believe that there will be no shortage of food whatsoever, so it can use excess energy to build your muscles. Skipping meals will make your body say 'crap! might not get any more food for awhile!!!! better break down that stored energy in my muscles just in case!! and pack on some fat too! yeah!!!!'
As for protein, you need to consume approximately 1 gram of protein for each pound of body weight, if you want to gain mass. So you need to eat 150 or so g or protein. That doesn't seem too crazy, but Plan9 told me that your body can only absorb 25g of protein at a time.... so you need to have 6 meals during the day that include 25g of protein. That's where protein shakes and bars come in handy, if you are pressed for time.
Be sure that you are taking in more calories than you are putting out - you can try counting calories and measuring your output if you have the time. I think
www.bodybuilding.com has a food database.
As for other foods, try tofu, chick peas, beans as well. Try fresh fish instead of canned - some people are freaked out by the mercury levels in canned fish such as tuna. Unless you eat 12 cans a day, you'll be ok with the canned anyway
For exercises, I swear by the site
www.exrx.net. Go to
http://www.exrx.net/Lists/Directory.html for pretty much every exercise you can imagine, with videos and instructions for each one.
Good luck!!!