I currently do around 3/4 different exercises of 4 sets/10 reps each per muscle. I have increased weight by more than double since I started, but I started really low.
5x5 means 5 sets of 5 reps per muscle group, right? If so, how many exercises for each?
5x5 is different, it includes only big exercises and not that many because it literally kills you. Here's what you do (there are some 5x5 variations but they are similar)
Day 1: squat, shoulder press, deadlfts (I skip deadlifts and do dips and pull ups with weights instead, though, that's just my choice)
Day 2: rest
Day 3: squat, bench, rows
Repeat. See, that way you do bench like 3 times a week which is amazing and legs 4. I for one get impressive results when going frequently.
But it's not really that easy, there are whole lot of things behind it (how and by how much you increase weights every day you go and when you do deloads). We had many discussions here about, many many, so I guess you can browse back. Zach even posted excel sheet of how it goes, easier to follow and he gave a great (long) explanation.