THIS IS A WORK-IN-PROGRESS TUTORIAL! GIVE IT SOME TIME TO MATURE!

Hair lair there, and welcome to my tutorial on how to create a Minecraft mod for 1.7.10, using Minecraft Forge. Let's get started.

Setting Up Your Workspace

Required Materials

You will need the following programs and materials:
1) Eclipse IDE
2) Minecraft Forge (see below for installation details)
3) JDK 8
4) Some sort of archiving program, like 7-Zip

Installing Forge

Upon clicking the link that should lead to the Minecraft Forge Files site, go to the list item that says "1.7.10-Latest", and download both the Installer (Mac and Linux users should click the link that says "Installer", Windows users should click "Installer-Win") and the SRC (it is labeled as "Src").

Once both the Installer and SRC are installed, you must do the following (this is where the archiving program comes into play): unzip both Eclipse and Forge 1.7.10 to a folder of your naming choice (preferrably to your desktop).

Now, open up your operating system's Command Prompt:
Windows - go to Start Menu --> type in the search bar "cmd" (w/o quotes) --> click the "cmd.exe" application
OS X -  Finder --> Application --> Utilities --> Terminal
Ubuntu - Let me know in the comments.

Type in the command prompt this command:
cd (drag and drop forge folder into terminal window)

Once completed, type in this command:
gradlew setupDecompWorkspace
This will fetch some resources required to create your mod.

Once that process is finished, type in this command:
gradlew eclipse
Once again, this is just fetching some resources required to create the mod (as far as I am able to observe)

Once those processes are finished, close your operating system's command prompt. When it asks for a workspace, choose the folder you created on your desktop. And if you done it correctly, BOOM! You're ready to mod Minecraft 1.7.10.

In case you're wondering whether or not you've done it right, are you able to see a "Minecraft" folder in the "Package Explorer" window of Eclipse? If so, you did it right.

Setting Up Your Main Mod File

1) Create a new Package in the src/main/java folder in Eclipse.
2) Name the Package youremailprovider.youremailaddress.com. This is to prevent confusion with other mod package names.
2A) Replace "youremailprovider" with whatever your email provider is. 
2B) Replace "youremailaddress" with your real email address.
3) Create a new Class, title it "Main" w/o the quotes.
Here's the sample code (courtesy of Minecraft Forums user IanTheSlime):

package youremailprovider.youremailaddress.com;

@Mod(modid="YourModsID", version="YourModsVersion")
public class Main
{
public static String MODID = "modid";
public static String VERSION = "version";

@EventHandler
public void preInit(FMLPreInitializationEvent e)
{
}

@EventHandler
public void init(FMLInitializationEvent e)
{
}

@EventHandler
public void postInit(FMLPostInitializationEvent e)
{
}
}


Setting Up Your Language File

1) Create a new package in src/main/java, title it "assets.YourModsID.lang" w/o quotes
2) Create a new file in the package you just created, title is "en_US.lang" w/o quotes.
For naming blocks, use this syntax:
tile.YourBlock.name=Block

For naming items, use this syntax:
item.yourItem.name=Item

And for item groups (aka the tab in the Creative Inventory), use this syntax:
itemGroup.tabName=Tab

If you have a question or concern, feel free to private message me or comment on the blog post. If you have a problem, leave it as a comment in the blog post, and I will help you as best as I can.

Creating Your "mcmod.info" file

First and foremost, the "mcmod.info" file basically contains metadata for Forge 1.7.10 to read.

With that explained, make sure that everything in "src/main/resources" is deleted (don't delete the directory itself).

Then, create the new mcmod.info file into the src folder. The example syntax is below (the sytnax is for an upcoming mod of mine):

[
{
"modid": "vegas",
"name": "Vegas Mash-Up Pack",
"description": "A random collection of different mods, currently a WiP",
"version": "$version";
"mcversion": "$mcversion";
"url": "",
"updateUrl": "",
"authors": "GunslingerN7"],
"credits": "GunslingerN7",
"logoFile": "",
"screenshots": [],
"dependencies": [mod_MinecraftForge]
}
]


You're ready to mod...

You are now an official modder of Minecraft. Here are some basic tutorials sectioned off.

Creating a Creative Tab

package youremailprovider.youremailaddress.com;

@Mod(modid="YourModID", version="YourModVersion")
public class Main
{
public static String MODID = "YourModID";
public static String VERSION = "YourModVersion";

public static CreativeTabs tabName = new CreativeTabs("tabName")
{
public Item getTabIconItem()
{
return Items.stone;
}
};

@EventHandler
public void preInit(FMLPreInitializationEvent e)
{

}

@EventHandler
public void init(FMLInitializationEvent e)
{

}

@EventHandler
public void postInit(FMLPostInitializationEvent e)
{

}
}

Credits

1) Minecraft Forums user IanTheSlime for basic information