The ARRL Has a good book to get you started. It's called Low Power Communication
As for radios, some build them and others buy them. The 2 most popular non kit QRP radios are the Yaesu FT-817ND and the ICOM IC-703+.
As for kit radios, there is Elecraft K1,K2, Oak Hills Research 100A, Wilderness Sierra, and may others.
For antennas, there are quite a few prebuilt ones you can get. But most just run a wire dipole that can be adjusted in length.
One other thing, since you will be running off some kind of battery, CW is the way to go. Some do do voice tho.
To give you an ideal on a QRP setup, this is what I am going to run with....
Icom 703+ and backpack
2 NiMih battery packs firstname.lastname@example.orgV
Vibroplex Code Mite key
Hope this helps =)