For this tutorial you will need to download several things.
1: A fresh minecraft_server.jar from here.
It’s important that you get the server.jar from the bottom of the page and not the server.exe. With the .exe it will not work.
2: Forge from here.
You need the Source files for this to work.
3. MCP from here.
Be sure you get the version of MCP that you need for the Minecraft version.
4. A fresh .minecraft folder.
This needs to be a new .minecraft without any mods installed and you need the META-INF folder.
After downloading these things you should start the MCP setup.
First you need to extract your mcp folder with 7zip or winrar. When you have it extracted you can see that there are a lot of files and folders. You wont use most of them though.
The first thing that you will have to do is run: updatemcp.exe.
This will make sure that you have the most recent version of mcp.
Next you have to get your bin and resources folder from your fresh .minecraft folder and place them inside of the jars map in the mcp folder. You also have to add the minecraft_server.jar.
After you have added all those files in the jars map you should get your forge source.jar and extract it here. It’s important that you extract it here and not in some other map. You have to get the forge folder between eclipse and jars.
Now you have to enter the forge folder and hit the install.cmd. This will install all the files you will need for Forge.
This is everything that you have to do to make your MCP ready to use. To actually use MCP you have to open eclipse. When you do it asks you your Workspace location. To get this the way you want you have to select the eclipse folder in your mcp map. You should just click the map and nothing inside there.
When you continue you can take a look at the Minecraft source code.