Mark A. Smith (forum)
http://community.logos.com/forums/p/32469/241957.aspx#241957
The ISBE is a great resource for learning about places, customs, theological concepts, archeological information, ancient civilizations, and other background information for Bible study, plus it contains introductions to all the Bible books and has articles on Christian living and ethical questions and just about any Biblical topic you can think of. It might often contain all the information you need, and if not it will be a good starting place for subjects you are not familiar with.
Mark Barnes (forum)
http://community.logos.com/forums/p/31000/229812.aspx#229812
The IVP dictionaries are quite different to ISBE:
- ISBE has medium-sized articles on pretty much every topic (the website says 9,000 articles). On the other hand, the IVP dictionaries have much longer articles on a smaller number of topics.
- ISBE deals with theology, but also with people, places and things. IVP only really deals with theological issues.
- ISBE deals with the whole Bible in an equal way. IVP deals with subjects from a particular slant (Paul, Background, Gospels, etc.).
If you’re thinking about ISBE, I’d also consider Anchor (more expensive, but also more detailed). There are several threads comparing the two, particularly this one: http://community.logos.com/forums/p/22656/169214.aspx