I've heard about how you can catch monsters but I haven't found out how .-. Can anyone help?
Monsters can be captured by crafting a Creature Capture Station at tier 4, then using that to craft Capture Pods. These pods can be thrown at small, grounded creatures with less than 50% health to have a small change to capture them.
This feature is not yet implemented at this stage of the beta.
6: Are Novakids in yet? Monster capture? Pets? Fossils?
Not yet! The beta is not feature-complete, but people sure seem to be having fun anyway. :)
EDIT: Patch Annoyed Koala 9/12/2013. Creature taming seems to still not be possible but patch notes show it is definitely on the way.
Added early implementation of creature taming (more features coming soon)
You can catch baby monsters, no nova kids or fossils, but I also don't know how to catch, or find them. My guess is simply to interact with E or the middle mouse button