Remember though if you are using VC games it wont fill them all, you need to download the full wii 3d cover file from gametdb.com and choose your covers cause it will fill a massive gap in your memorys sd card and most games you will need to hunt around for covers, they are on the net but you need to look hard! Try the cover section here below, there are a lot of VC covers done already some nice ones as well
Everything and all links are already provided in Loadiine's first post guide.
can someone tell me why did I spent my time to write something nobody read already?
• + on wiimote will download from gametdb.com, you need to proper TitleID6 for WiiU games or titleID4 for VC games set in your folder or meta.xml
• you can download manually all covers at once from gametdb.com if you want and extract on SD card. (grab the english package first, and then complete/overwrite with other language if you want or you'll miss a lot)
• if a cover is missing, you can contribute to gametdb and help other users getting it
• if you have/want a custom cover, you can post in the thread Reecey gave above.