First off. Do not buy that book above. It's useless. You want to gain weight but your an ecto. If you want to gain weight you have to find out how much your daily maintenance of calories are. Do this by googling BMR calculator. Use a couple different to gauge how much your body needs. To gain about a pound a week, theoretically, you eat 500 calories a day more than maintenance. This will take some time to gauge due to metabolism, activity level etc. Just check your weight weekly and adjust accordingly.

In terms of lifting weights. First rule of thumb. DO NOT WORK OUT FOR MORE THAN AN HOUR (unless your on the juice but I assume we're keeping it natural). Don't do any cardio it's just not needed especially if your bulking. Since your just getting back into the swing of things stick to a 3'day split consisting of compound movements is bench, squat, Deadlift. Google some programs there's hundreds out there. The main thing u have to do is eat eat eat. If you can't stomach a lot of food start off by getting a weight gainer. optimum nutrition sells a good one. Just look for Reviews.

I'm at work so I couldn't respond as detailed as u probably needed but reply with more questions and I'll definitely give you the help you need.

Thanks for that.
First off, I never stay in the gym more than an hour/hour and a half, and I leave at least 48 hours between exercises that require use of my arms and indeed no cardio.
I'll be sure to check out Optimum Nutrition, but I've heard True-Mass is generally the best (?) so I'm more inclined on using that again.

Harris Benedict formula:
1527(BMR) x 1.55 (moderately active)= 2366 is what I need to maintain my current weight.
True-Mass Weight Gainer = 630kcal x 3 = 1890

Let's say my aim is to get 3000-3500kcal every day (not sure if my body can handle this at the moment)

This is the foodplan I have for myself, what needs changing?

8.30:
Peanut butter (one spoon)
4 raw eggs (1 full, 3 only egg white)
muesli + full yoghurt & sugar
1 fruit (strawberries, banana, apple)
10.30:
True-Mass shake
Banana
12.00:
100 grams of carbs (rice with curry sauce)
100-150 grams of proteine (tuna or chicken)
vegetables (piece of cucumber or piece of paprika)
15:30:
True-Mass Shake
Banana
18:30:
Dinner (this varies, anything important I should eat at this time aside from Proteine & Carbs?)
20.00:
Gym
22.30:
Fruit
Peanutbutter (one spoon)
Proteine Shake (Caseine Protein)

Don't drink raw eggs! you can buy pasteurized egg whites at the grocery store in a carton and that is the way to go. Eggs must be cooked or your body will not be able to process most of the protein. When eggs cook they undergo a process called lecethinization. This makes them easier for your body to digest them as lecethin aids in protein digestion. Pasteurization heats the egg white up enough to make the protein absorbable but also kills salmonella, and it's still in liquid form for your shakes. Basically raw eggs can do more harm than good so just buy the egg whites that have been processed properly for consumption.

You need to spread your total macro intake evenly across meals, with around 50-60% of your total daily carb intake being ingested in your preworkout and post workout meals. Also, no peanut butter or other fats post worout. You should also be having a whey protein not a casein protein shake postworkout coupled with High GI carbs such as pasta, white rice, potato for example.