Can I merge my iTunes Library with my husband's library?

Apple IDs cannot be merged...

From Here http://support.apple.com/kb/HE37

I have multiple Apple IDs. Is there a way for me to merge them into a single Apple ID?

Apple IDs cannot be merged. You should use your preferred Apple ID from now on, but you can still access your purchased items such as music, movies, or software using your other Apple IDs.

What about Home Sharing? I move stuff from my itunes library to my children's because we use the same computer.....

http://support.apple.com/kb/ht3819

Just to make it clear, AppleID/iTunesID is not the same as an iTunes library.

iTunesID is used to make purchases in iTunes store.

iTunes Library is on your computer with the media.

We'd like to combine both libraries under one account

Do you mean under one computer login user account (not iTunes account)?