If you're getting white blocks over things, I think this will help:
How to install mods and MCpatcher.
Step 1: If you are using any mods that require the mod loader then the mod loader MUST be installed first. This also includes the sound mod. If you don't know how to install the modloader all you have to do is locate the minecraft.jar in the bin folder of the minecraft folder. If you are running windows you can find this folder by clicking the start button and typing run. When the next window pops up type "%appdata%\.minecraft" without quotations and it will open the minecraft folder. Then navigate to the bin folder and open it. Find the minecraft.jar and open it with a decomplier(or unzipper) like winrar or winzip. Do the same with the modloader.zip. Then transfer the files from the modloader to the minecraft.jar and delete the Meta-INF folder.
Step 2: Patch with MCpatcher but DO NOT patch each individual texture pack. The older versions of MCpatcher used to work like that.
Step 3: Drop and and all texture packs that you want to use into the texturepack folder in the minecraft folder
Step 4: Then install any other mods. If you are using a mod like the yogbox that comes with it's own installer Then you must use Optimine/Optifog instead of MCpatcher.
Note: Installing optimine/optifog is just like installing the modloader