RE: Probably the wrong forum...but
let me break it down to you mate, putting on muscle is about the hardest thing you can do, as you say, you have weight trained for a year and have gained little or no muscle.... so don't worry about bulking... if you find you get too big, or big enough, just stop bulking and cut the kcal intake down. not absolutely essecary to bulk then cut, but results come 10x as fast doing it tht way.
basically have no fear of doing 5x5, its not like you'll be ronnie over night!!