Just imported the movies into iTunes. iTunes would have put whatever you imported into the correct location.
If iTunes can play them then you would have been golden.
Nothing to do from that point other than to sync the movies onto the iPhone.

Regarding the missing Library. As you named the new library something other than what the original library was named, that library is still there. (somewhere)

Although My Music is the default location for the iTunes library, it could be anywhere.
The usual places are:
Windows XP: C:\Documents and Settings\username\My Documents\My Music\iTunes\
Windows Vista: C:\Users\username\Music\iTunes\
Windows 7: C:\Users\username\My Music\iTunes\

Have you tried using your systems search function to find it?