In your CM3 directory you'll find a file called "piced.exe". I think most of you found out that's a picture editor for CM3 backgrounds and menubars (that's the bar left to the background picture), but how to use it and how to apply the changes to CM3? Here's the answer:

1a. How to make a CM3- background picture:
Before you use the picture editor look that the picture you want to add to CM3 fulfils the requirements. It has to be saved as a 24 bit bitmap (*.bmp)- file, 800 x 600 pixels. A bigger or smaller picture is also possible, but you'll see yourself that it won't look good then.
Now run the picture editor, choose "Load", then "Background Bitmap". Enter the path to your image which you want to make a CM3- background. Now click on the filename of this image and say "OK". If you now see your image in the background, it's possible to save it as a CM3- Background. If not, check if it fulfils the requirements. Now simply click on "save" and enter a name for the picture. But before you click on "OK" look that it gets saved in the picture folder of CM3.
P.S.: Background pictures are saved as *.rgn files.

1b. Add the new background picture to CM3:
To add a new background run a simple texteditor, e.g. notepad. Open the file "pics.cfg" which you'll find in the pictures directory of your CM3. This file controls which background-image will be loaded for certain situations in CM3.
You've the choose to connect your picture to a certain club, nation, competition, stadium or person. It's also possible to connect it with more than one event. I think you'll see what to do when you've opened the file, but anyway an example:
To connect an image called robbiekeane.rgn to Coventry, Ireland and the player Robbie Keane, and another image to Ireland write this:
below [CLUBS]: Coventry: robbiekeane.rgn
below [NATIONS]: Ireland: robbiekeane.rgn, ireland.rgn
below [STAFF]: Robbie Keane 8/7/1980: robbiekeane.rgn
That's all.

P.S. If you play without background changes (Game Settings -> Background Changes = Off) and you don't want always to see that ugly Ole Gunnar Solskjaer in the background;) - Go to your CM3- Data directory and replace the file default_pic.rgn with an other picture (name also has to be default_pic.rgn!)

As you now know how it works - why not download a background picture right now?

2a. How to make a menubar picture:
The picture you want to make a menubar picture has to be saved as a 24 bit bmp file with 90 x 600 pixels. The steps to load and save are the same as mentioned above for the background picture, but you only have to save it in the "data" folder.

2b. Add the menubar to CM3:
In the CM3- Data folder are two files called game.mbr and match.mbr. This are the two standard menubars that are used in the game, match.mbr when you're currently playing a match, and game.mbr all the other time. So when you want to add your own menubars you've to give them this names (=overwrite or rename the old ones). Note that the menubar doesn't change automatically when you change your club, you have to change it manually. Also it isn't possible to load different menubars in CM3, e.g. Jimmy is managing Arsenal and Johnny Juventus, they can't use their own menubar each other, they have to agree on one. In such cases it's perhaps better to play with the original, neutral- blue menubar...

A few ready-to-use-menubars are available at the download area!