The best book for your purposes, in my opinion, is "Petroleum Processing" by R.J. Hengstebeck of Amoco (McGraw-Hill, 1959). It's out of print but libraries should carry it. This is an incredibly lucid book, written by one of the masters.
I studied with Professor Nelson and his "Petroleum Refinery Engineering" (4th edition, McGraw-Hill, 1958) is the definitive work on the subject, but it may contain more detail than newcomers can handle.
Also, look for "Petroleum Processing Handbook" by Bland and Davidson (McGraw-Hill, 1967) for explanations in a nutshell for a wide variety of processes. This also has an excellent section on light hydrocarbon and petroleum fraction physical and transport properties. Finally, there is a vast list of references, a bit dated of course.