CS : SOURCE CHEATS :]

Cheat	Effect
sv_gravity #	replace # with number to change gravity
r_shadowids 1 with sv cheats on in console	moving numbers on screen showing players shadows
impulse 101	16,000 cash
cl_crosshairscale 4000	small crosshair, doesnt get bigger or smaller
phys_pushforce #	Flying Bodies/Objects
noclip	let's you fly around the map and not get hurt
net_graph 0	Won't show stats at bottom of screen
net_graph 1	Show's stats at bottom of screen
host_timescale *	Replace * with a number to get the desired speed. Don't go too high or your server/CSS will crash. Higher you go, less FPS and vice versa.
mat_wireframe 3	See through walls.
sv_showimpacts	Puts a square where bullets hit. Very useful for learning how to control sprays. Sv_cheats is not required
mat_proxy 2	Clear walls.
r_drawothermodels 2	Wireframe player models.
impulse 99	Skulls drop from sky.
props!	spawns props.
settings	allows you to change skin
mp_c4timer #	Replace # with a number to change c4 detonation time

Cheat

Enter sv_cheats 1 in the console, after typing in the enitial code, enter noclip at the start of every turn to activate the cheat.
Note: This only works for Administrators (server operators), you can start your own bot server and use it there if you wish