It takes a while to get used to weights if you are new to it. I would go with what you are comfortable with doing 10-12 reps (repetitions) to condtion your muscles, so dont worry about strggling with the basics as you will gradually develope your upper body strength (just remember to slightly increase weight each week, again, with weight you can do for 10 reps). The thing to consider here is not to try and go heavy str8 away as this could lead to injury and b4 you know it, you can train for a long time.
Once your muscles are conditioned (which could take min 3 weeks for some pple), you can then focus on try to bulk up by going heavy weights (NOTE: your heavy and someone else's heavy aint the same, so go with what u would consider heavy) and low reps, so anywhere arnd the 8 rep mark.
Mondo's routine is pretty good, he's incorporated the bulk building blocks:
* Barbell bench Press
* Deadlifts (which work your whole back if one correctly)
* Squats (if u were thinking of doing legs)
Always slip in one of these in your work out.
And as he also pointed out, triceps are the ones that make your arms look bigger, so train them equally with your biceps. try super setting them to get a good pumped feel e.g. DB Bicep Curls x10 and straight away do DB Tricep Kickbacks x10).
As for how many times to workout, 3 days a week; alternating e.g. mon, wed, fri or whichever you prefer (to let your muscles grow on resting days).
But the most IMPORTANT thing for bulking up is your diet; you have to eat like a monster
Eat more carbs:
Lots of pasta, sweet potatoes etc
Proteins:
Egg whites-can get them from health food shops
Skinless Chicken Breasts, i go through 6 a week
Protein powder - dont burn your money with all the expensive flashy ones, any whey protein concentrate-WPC (more for building muscle) or Whey protein Isolate WPI, more expensive (more for toning up)
Fats:
Flaxseed oil - comes in capsule form or str8 in a bottle
Hope this answers most of your questions.....