If you are a sole proprietor or single member LLC, you can file as self-employed on Schedule C (unless you elected to be taxed as an S-Corporation - then it's a Form 1120S).
If you are a Partnership or a multi-member LLC, you will generally file a Form 1065 Partnership return. If have an LLC and only you and your spouse are members, you will file a Form 1065 Partnership return unless you live in a community property state (then you can file two Schedule Cs).
