I just started my channel and am averaging around 3-4 subs every week, it's a different process for everyone. The numbers really depend on a couple things. First off, the most confusing thing is audience size. If you have a large audience size, it's hard to get started, but once you get big, you grow really big, and exponentially. With smaller audiences however, you can normally gain a following pretty fast, but once you make it big, you gain tons of subs for a couple months, and then the growth dies out, cause there aren't enough people to subscribe to you to make you really big. The easiest thing to understand, which is the one everyone should be working on, is quality. I don't mean "Oh, I'm gonna get a new microphone/camera/computer/etc. , I mean the actual video. Is it funny, is it interesting, that sort of thing. Your best friend in that department is editing. Spend more time editing, and if you think of a really cool effect, but it will take an hour or two, do it! If people realize that, for once, someone on this platform called YouTube is actually putting effort into their videos, people will come. I saw a drastic difference in growth when I switched from bare-bones let's plays to highly editing funny moments. I hope this helps you, and have a wonderful day!