I started writing this, then I lost interest because of how easy CleanRip is to use. Feel free to take this and use it.
Tools
Getting Started
Your first steps will be hacking your Wii. See the "tools" section for information on how to do so.
Start CleanRip. Read the disclaimer and press A. If you do not have IOS58 installed, CR will warn you. If you plan on dumping to USB, install IOS58. If you will dump to SD, performance will not be effected. (You will be bugged to install every time you start the app without IOS58, so it may be a good idea anyway.) Select your dumping medium. Press A when your dumping device is inserted into the Wii. Press A to download the newest DAT from Redump.org (Internet connection required). Press A when your disc to be dumped is in the Wii.
Wii discs
Dual layer: No*
Chunk size: [Largest size that will fit on your SD card]**
New device per chunk: Yes.***
*99% of the time. Check online to see if your game is larger than 4.3 GB.
**Max only works on NTFS formatted devices.
***Only use [no] if your device can hold a full game dump (1.3 GB for GC, 4.3 GB for Wii).