There are a lot of marketing books these days, a lot of them concentrate on online marketing and new marketing techniques. But I'm looking for some great books, which you found quite useful, yet they are pertained as marketing classics. For example, I've read Positioning: The Battle for Your Mind by Al Ries & Jack Trout quite recently - the original version was written around 30 years ago! But I still found a lot of great ideas there, although it's a bit over filled with examples, instead of actual advice. It also helped a lot in understanding how marketing developed. There are a lot of tips/book suggestions online, but I would really love to check out what you, guys, have to offer
If you want classic books there is How To Write a Good Advertisement by marketing legend Charles Schwab. It deals with the copywriting aspect of marketing. It was written I think in the 1950s but it still has lots of timeless advice about how to market to people.