There's no official guide, per se, but the easiest way to get the other endings is:
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For the Romance end - Put off going back into cryogenic sleep until the last possible moment and then make sure you ask Silas to promise you that he'll be there when you wake up. If you don't see a dialogue option to make him promise, you have to continue insisting that you won't sleep...
To get the "normal" end or the non-romance/non-friendship one, just go back to sleep right away and make sure you DON'T ask about Silas after you've been rescued.