Alright I have played my fare share of competitive leagues for CS:S. So I am just going to write down what I know so if you want to know how I do what I do you can.
Aiming - The way you aim is different for every single gun in the game and what I mean by this is trying to control recoil. It can be extrodinarly frustrating. The number one question people get asked for shooting is how do I no scope. Well my answer to you is how I do it which will work for anyone and allow you to no scope. First thing you need to do is get down the timing for stop and starting running. so you are running right and you tap left before you fire. There is a brief instance there where you are not in motion it is during this time that you must fire. The main problem with this is the fact that you still have to control recoil. You do this by making a small circle about the size of this symbol
and shoot on your way up. This will allow you to no scope. Getting this down takes a whole lot of practice. For each weapon there is a way to shoot it and I am not going to explain this as they are fairly easy to learn to control. What i am going to tell you is how to improve your aim. There are a couple ways of doing this. To improve your reaction time i suggest playing a game called reflex_2. To improve your aim i suggest 2 weeks worht of dm at 2hrs a day with glock or usp.
Sound- the only way to really practice sound is to play in CAL/CPL servers, esea or scriming.