Unreal Engine 4 has some specific hardware and software requirements for running the game and editor or developing with the engine, check them before downloading the Squad SDK.
Following are the current system requirements:

Unreal Engine is the engine used by the SDK itself and also by the game, there are also a lot of tutorials and documentation on the official site on how to use it.
In order to download the Squad SDK, you will need to download the Epic Games Launcher. The Epic Games Launcher is a global launcher that contains several games, Unreal Engine 4 and also several Modding SDK's including the one for Squad.
1.Go to the Unreal Engine website. https://www.unrealengine.com/en-US/what-is-unreal-engine-4
2.Click the blue "Download" button, in the top right of your browser.
3.Register for your free Epic Games account.
4.Download the Epic Games Launcher.
5.Install the Epic Games Launcher.

Once you have downloaded the Epic Games Launcher you should:
1.Sign-in using your Account.
2.Locate the "Modding" Tab, on the far right of all the tabs.
3.Find the Squad Development KIt and click "Install" and then read and accept the agreement.
After your installation has finished, the green "Install" button will change into "Launch".

This FAQ has been compiled to answer the most common questions asked by modders. It contains questions and answers related to the Squad SDK and the Steam Workshop.
1.Q: What engine version should I be using for the Squad SDK? You don't need to worry about engine versions! The Squad SDK automatically comes with the correct engine version when you download it through the Modding tab on the Epic Games Launcher.
2.Q: I launched the Squad SDK but it's taking a long time to load. What's wrong? If it's the first time you're launching the Squad SDK it will take a while. Load times vary depending on your hardware but you just have to stay patient! It has taken anywhere from 10 to 40 minutes based on general reports from members. There have also been cases where having NVIDIA Shadowplay enabled caused longer load times, so it is advised to disable it while you load up!
3.Q: Can my map / mod be added to the base game? Yes! There's a possibility of mods that match the developers' level of quality being added into the base game. Examples of this so far are Al Basrah, Russian ammo crates, Mestia, Kokan and extra vehicle seats, which were all made by community members.
4.Q: “The editor says my mod was successfully uploaded the Steam Workshop but it's not live.” It is possible that your item is on the Steam Workshop but not Public. This happens if you have not accepted Steam's Workshop Terms of Service. Please accept the Terms of Service, then go to your Steam Profile and look at your Steam Workshop content. Then go to the mod you uploaded and set its visibility to Public.
5.Q: “I can see my mod on the Steam Workshop but no one else can.” This is because you have not accepted Steam's Workshop Terms of Service. Please accept the Terms of Service, then set your mods visibility to Public.
6.Q: “I got an unknown error when uploading my mod to the Steam Workshop.” Please post in the Squad Modding Discord channel “Steam Workshop Support”. Please also share your: depot_build_393380.log file. This file is located in Steam/workshopbuilds.
7.Q: “I can't join the server even though I have all the mods.” Make sure you leave the game and see if mods are downloaded and installed. If it does not work, check whether you are subscribed to a mod, then restart Steam. You will then see Steam Workshop content being downloaded. After it's downloaded, restart the game.
8.Q: “Why can't I join the server that is currently on vanilla map?” If the server has modded content in its rotation, you will get a message with a link to the required mod, that you will need to install. This means you can't join the server until you have the mod installed. Note: Make sure to restart the game, then download and install the mod.

#Due to removing a lot of our core art assets some of the physical material setups used by the maps will show errors when loading example maps. This is fine and will not affect your map
#There may be some static weapon assets in the environment folders with broken materials. They are not to be used currently.
#While the default US player models are still in the build they are not setup to be used as a team. (You could figure out how to clone the Russian team though) Please don't try to use them as a faction player without first understanding how they work.

The Squad SDK is shipped "As is" and we offer no guarantee and/or warranty that it will function with your specific hardware setup. EULA is the license of EPIC games when you install Unreal Engine 4. Any violation of those terms is the sole responsibility of the user.
Feel free to rip this stuff apart and poke around but do not attempt to export or reverse engineer assets to any other program. Doing so will result in immediate and permanent loss of access to Squad at Offworld Industries discretion.

If you need support or want to discuss the SDK with other members of the community working on maps, you can join the Squad Modding Hub at this link: https://discord.gg/0jXt1Y2dpl79B4qV

This Guide was mainly displaced from squad.gamepedia.com.

Squad Wiki Contributors. (December 25, 2017). Squad SDK. https://squad.gamepedia.com/Squad_SDK