SET CORRECT RATES!
Rates are very important in Counter-Strike: Source. Correct rates settings provide smooth gameplay to you and other players on the server. It doesn't take a long time to set it. You need access to the game console. By default it is disabled. To turn it on, press ESC, go to game OPTIONS and then Keyboard tab, click on Advanced... button and mark Enable developer console (~). Click OK, OK... Now you have to open console by pressing ~ . You can enter there a various game commands. All commands have to be accepted by pressing Enter key. Let's change rates now. Correct settings are (every line is one command to type and accept in the console):

rate 30000
cl_updaterate 66
cl_cmdrate 66
cl_interp 0
cl_interp_ratio 2
cl_lagcompensation 1
cl_smooth 0