I'm going to skip Chapter 17, it's basically about rules, rods and magic tricks. In fact, I'm starting to get a sneaky suspicion that's what the the Bible's really all about, if you take into account all the possible puns and implications. One interesting thing about Chapter 17 - God threatens to kill people who murmer.
In Chapter 18, the most important thing is that God says that only the Levites can sacrifice animals, and that Israelites must give a tenth of everything they have to Yahweh, and then any leftovers from that will go to the Levites.
It's starting to get repetitive, too. We're begin repeating a lot of stuff that was mentioned in all the other books: sacrifices smell good to Yahweh, non-Levites approaching the Tabernacle will be killed by Yahweh, etc. The verse in particular that says that is "strangers that come nigh", which could mean that any stranger will die, but in context it sounds like non-Levites.
Chapter 19 is more stuff about animal sacrifice. It talks about the proper purification ritual to prepare sacrificing a red heifer.
Actually, a lot of Jews and Christians are looking forward to the day that a red heifer is born. Apparently, red heifers are very rare. Well - a red heifer has been born fairly recently and both Jews and Christians are longing for the day it can be sacrificed. Somehow, the sacrifice of this red bovine will bring on the end of the world.
If it does, it's because of a bunch of crazies are out there actually pushing for the end of the world.