My main complaint against this book is the author's name. (In case you're American or something, "randy" means much the same as "horny".) What kind of parents give their child a name like that, unless they want him to be a gigolo or something? "Hi, I'm Randy, nice to meet you!" Anyway, it's a very good book, even if the author does have a silly name.
The basic point of the book is that Jesus asked people questions and listened an awful lot more than most of us do when talking to people about Jesus. Being asked questions helps people think about what's being said. Although the focus is specifically evangelism and apologetics, a lot of what's said is applicable to more general conversation as well, which is especially helpful for rubbish conversationalists such as me. I guess learning to integrate what I know about pedagogy into how I do conversations (both ways) would be useful...
Probably the secondary point is that it's important to love people and care about them. The examples given of where this goes wrong mostly seem to be tied into the culture wars in the US and so are of slightly less relevance to the UK situation, but it's nice reading an American saying what seems obvious to so many in the British church. (I wonder what problems in British evangelicalism are invisible to us but obvious to Americans...)
But all in all, a great book, and very helpful for thinking about how to do personal evangelism and stuff.