SQL Service Account creation in AD using PowerShell
If you have installed the Active Directory PowerShell components, and the account under which you are running the session has sufficient permission to perform the action, then it is actually pretty simple:

New-ADUser -Name "Jo Bloggs" -GivenName Jo -Surname Bloggs`
-SamAccountName jbloggs -UserPrincipalName jbloggs@corp.contoso.com `
-AccountPassword (Read-Host -AsSecureString "AccountPassword") `
-Path 'OU=Whatever,OU=Blah,DC=corp,DC=contoso,DC=com' `
-PassThru | Enable-ADAccount


The documentation is pretty extensive and can be found here:
https://technet.microsoft.com/en-us/library/ee617253.aspx