*This part of the tutorial is geared towards Windows users. The MAC instructions are very similar. Install the package the same way. All ADB/Fastboot commands may need to start with "adb-mac" (no quotes) rather than "adb" (no quotes). Due to the vast amount of Linux distros available; instructions will vary for your device. Once ADB/Fastboot are set up all command will begin with "./adb" (no quotes) rather than "adb" (no quotes). Once ADB/Fastboot are set up; this guide is relevant to everyone.*

Setting up ADB
Download AndroidSDK
Note: Google changes their mind every other week as to if this will be distributed as a .zip or an .exe. If you get an .zip file, simply extract the contents to your C:\ drive. For an .exe install it like you would any other program, but set the path directly to the C:\ drive when the installer asks.

Or...you can use this page to download the "ADB for Dummies AIO App."
This will automatically install ADB for you to your C:\ directory. It's very simple this way.

If your platform-tools folder doesn't have a fastboot.exe, place this fastboot.exe file in your C:\android-sdk-windows\platform-tools (or possibly simply called tools, if you set up ADB ages ago) folder.

Now you have ADB installed! Congratulations.

***NOTE***This may perform a factory reset on your device. You will lose all your APPS & DATA. Even the data on your SD Card! I'd recommend making a Backup to your computer BEFORE performing this.

Get the drivers
Uninstall any previously attempted drivers if they don't work and move to the next.
Option One: Steps 16-27.
Option Two: Try this one as well. Use CyanogenMod's Guide for installing ADB - Steps 16 through 27 replacing the file/location with the naked drivers.
PDAnet's drivers may work if the above options don't. Simply install PDAnet (after uninstalling any previous attempted driver installations) to get the drivers.

While that is downloading, on your Nexus 4: turn USB debugging on.
To do so; you must first go to Settings>About>Build Number and click seven times.
The actual setting can then be found in Settings>Developer Options>USB Debugging

Once the drivers are installed, navigate to the C:\android-sdk-windows\platform-tools folder on your computer.
Hold shift and right click. Select "Open Command Window Here."
On your phone: turn USB Debugging On. To do so; you must first go to Settings>About>Build Number and click seven times.

The actual setting can then be found in Settings>Developer Options>USB Debugging
Plug your phone into the computer. Now in this command window type:

If your Command Prompt displays the message "waiting for device" your driver wasn't successfully installed.
Close the Command Prompt window and open Device manager while your phone is still plugged in. (Search for it using the search option).

Right Click the "Android" option and select Update Driver. Choose to "Browse My Computer" and "Let Me Pick From A List." Pick the Driver with the newest date and install it. Now retry the code above.
Your phone will ask if you want to unlock it. Select "Yes" by using the volume keys and use power to select it.
Now, navigate to "Recovery Mode" with the volume keys. Use power to select.

A screen with another Android will pop up. Press Volume Up and Power at the same time.
Select Factory Reset. This process may take a few minutes. Be patient and let it work.
Once finished, select "Reboot."

Your phone is now unlocked!

Obtaining Root Access and Custom Recovery:
Turn on USB Debugging: To do so; you must first go to Settings>About>Build Number and click seven times.
The actual setting can then be found in Settings>Developer Options>USB Debugging
SuperSU(CWM .zip)
CWM (Pick the version for your device)

Place the recovery-clockwork-VERSIONNUMBER-mako.img file into your C:\android-sdk-windows\platform-tools folder.
Put the SuperSU.zip on your phone.
Open another Command Prompt if it isn't still open. (Navigate to C:\android-sdk-windows\platform-tools and shift + right click. Select "Open Command Window Here.")
With your phone plugged in type:
adb reboot bootloader
(Hit Enter)
And wait for your phone to boot into the android again.

Now type:
fastboot flash recovery IMAGENAME.img
(Change the file name to the correct file name and Hit Enter)

Once that is finished: select the "Recovery Mode" option again on your phone.
You should get a new recovery menu here. Select "install zip from sd card" and "choose zip from sd card."
Find the SuperSU.zip that you transferred earlier and select "Yes" to installing.
Navigate back to "Reboot" and reboot your phone.
You're now rooted!
However, ClockworkMod Recovery won't continue to load after this.
To fix this, find "Rom Manager" from the market. (The free version is fine.) Use the "Flash ClockworkMod Recovery" option.
If your recovery still doesn't stick around after a reboot, you have another couple options. Find a file explorer that allows root access, such as Root Explorer. Use this program to rename /system/etc/install-recovery.sh to /system/etc/install-recovery.bak. You'll need to mount the system as r/w to do this. Root Explorer provides a button at the top to do so. Or, you can do this completely manually by firing up ADB again and running a few commands:


Congratulations!
Your phone is now unlocked, rooted, and has a custom recovery!

***I take no responsibility for what happens to your phone due to following this guide! That being said, not only am I sure you'll be fine...but there are an endless amount of users who would be glad to help if you need it.***

Download the rom you'd like to try on your device. Most roms also required you to install "gapps" as well.
You can find the correct ones for the rom you're using in the ROM thread. Make sure the ROM and Gapps are on your virtual SD card directory.

Now, open Google Wallet (if you have it installed) and press Options>Settings>Reset Google Wallet. This will prevent the "Secure Element" errors some users have experienced.

Boot into ClockworkMod Recovery by turning your device completely off. Hold volume up, volume down, and power until the green Android with the open chest is displayed. Navigate to "Recovery Mode" with the volume buttons and select using the power button. Remember to have a recent nandroid before continuing!
Navigate to "wipe data/factory reset" and select it. Select "yes."

Wait for the process to complete. This may take some time. Be patient!
Once complete: Navigate to "Install Zip from SD card" and "Choose zip from SD card."
Find the rom's .zip and install it. Once that completes install any applicable gapps' .zip. Select the "Reboot" option.

Congratulations! Your phone should now boot into the custom rom!
Follow the prompts to re-activate your phone.