I'm totally lost as to all the new armors and weapons and staffs and thingamajigs. I've been playing on Tekkit lite or a custom made server with the Buildcraft and Redpower mods my husband likes, so I have no experience with most of these mods. That said, we have both been having a blast discovering new items, monsters, dungeons, etc. We've gotten stuck trying to kill the pirates on a ship we found, but they regenerate like mad so we've got that on hold until we figure out some of the fancy-shmancy weapons that'll kill those bastages.
I'd say explore, figure some of these things out for yourself, and keep checking the wiki for new information when you get stumped.