How to find memory addresses in Cheat Engine (With pictures, works in most games)

Since this works for multiple games, I posted it in the General game hacking section.
This works with almost every game type, FPS, TPS, RPG, RTS, and I mean almost every game.

A few things before the tut: You can get banned in Multiplayer games, such as Modern Warfare 2, for doing this, while in game, or leaving CE running while in game.

Some games have Dynamic addresses, which means you have to search for the addresses every time you restart the game, lose focus of the window, or reach a checkpoint in some games.

Tutorial: In this, I'm going to use Doom 3 as an example.

1.
Download and Install Cheat Engine
Since I can't give external links (Unless approved by minions or mods), just use Google to search for Cheat Engine.

2.
Open Cheat Engine and Attach It To a Process
Click on the little computer in the upper-left part of CE

Now choose the process:


3.
Health and Ammo
Look for your current health or ammo:

Now search for the address in Cheat Engine:

Intentionally lose some health (Use explosives, fall down somewhere etc):

Now search for the new value in CE:


You should be left with around 4~8 addresses, then lose some more health, then search for the new value again:



You should be left with a single address, which is most likely the correct one for Health. Double click this address to add it to the list, then double click the Value part, then change it to 999, and then freeze the address. If you notice in the next pic, I'm not losing health for being caught in an explosion (It goes down for a very brief time, then goes back to 999):




The procedure for ammo, or EXP or kills in other games, is basically the same.
Search for the original value, then get a higher value (For example: In Fallout 3, if you have 100 EXP, search for that value, then kill something and get 50 EXP, search for 150 EXP).

But just for the hell of it, I'll show the end result of using Cheat Engine to search for ammo (Notice the ammo counter):



Tips/Warnings:
Don't do this in multiplayer games in game unless whatever Cheat Protection it has is disabled, otherwise, you could be banned.

When you can't find an address, DO NOT do this:
Especially on your concrete floor, I broke all of my toes on my right foot by doing that (I'm not joking).

Some games addresses, such as the example game (Doom 3), have dynamic addresses, which means you have to search for the addresses when you restart the game.

In games like Halo: Combat Evolved, the addresses change whenever you hit a loading point, or in the case of Shaiya, there are a few addresses in that game that change when you lose focus.

In games like Runescape, Shaiya or WoW, trying to hack EXP or money WILL NOT WORK because they are server sided.

Try running the game in Windowed mode. In Doom 3, it's very simple (This one also works with COD4):
Open the console by pressing Control+Alt+Tilde (~, the key right next to 1), type in "R_Fullscreen 0" (No quotes) then press enter, then type in vid_restart, then it will restart the game engine (No progress in the level will be lost or anything).

you know that there is a cheat that gives you inf life/no??

Did you even read the entire post?
I just used Doom 3 as an example game, this isn't just for Doom 3 xD
I could use every game I own as example games, but the post would be about 58 pages long.