Lots of good advice here! Bob's setup guide is a great way to get introduced to all the settings, always good to have it within reach. I like to keep a notebook, writing down changes as I go, and my perception of those changes on my driving. I'm not a pro, I can't effectively tweak the suspension yet, but I fiddle around with everything, and try and write down as much info as I can. Paying attention to things like, tire temps, corner entry speeds, apex speeds, exit speeds, and over/understeer tendencies in certain corners.
From my experience, it's a good idea to start out with a specific goal. I'm sure you could use 'go faster!', but something a little easier to gauge helps to break things down into smaller chunks. I spend time working with my tire pressures and camber, making sure that my tires will stay at some consistent temperature for decent length stints. Nowadays I play with pressures first, and leave fine tuning the camber assymetrically til later in the process.
My next goal is to look at my corner entry speeds, compared with others, and see where I'm losing time. I don't like being passed, so I try and make sure people aren't much faster than me entering the corner. To achieve this I play mostly with coast differential, roll bars, and wings. By reading the guide and playing with these 5 settings, you'll be able to figure out which ones give you over/understeer, and in which ranges they work.
I don't worry about mid corner, because I find that if I can get it turned in, I can usually hold on for the ride. My solution for mid corner is pretty much practice practice, of course this advice goes for everything I've written
Corner exit is mostly by feeling out where I want the power differential. I like a little bit of oversteer, so that's what I aim for here.
Then there's the straight parts. I'm don't have much advice here. The one thing I do know, top speed is less important than cornering speed, usually
I wouldn't consider any of this real advice, but I remember being in the same spot you are now, a good intention of going faster, but no idea where to start. You've just got to find a method that works for you, set some goals, and practice alot. Patience is key, usually I don't have enough of it though!