is it normal for the male partner to be nervous or not sure what to expect to see during labor?

Yep!  You've met men who are really icked-out by periods, right?  It's that whole 'fear of the unknown' thing - they're so removed from how our bodies work (because they've got a 'pump and go' system for reproduction, where we have a long cycle with a lot of steps, then pregnancy with even more stuff) that it's easy for them to just get weirded out by it all.  So, just hug him, tell him he's going to be fine, and then invest in a doula for the labor (it'll be about $500, but well, well worth it).  A doula is like a 'mom for the new mom' during labor - she's there to take care of you so you don't have to.  It would definitely help your husband/partner out, I think :)