There are a few things
Dennis Hessler at http://www.spyglasspoint.com has some free info you might find interesting.
Also, contact your local customs authorities and ASK them what the rules and regs are.
Can you import wood? What are the rules?
Products with certain chemicals (cosmetics, for example)? Check the rules for pre-approved chemicals. Can't have flora and fauna being killed off. Every country has different F&F so has different things on the list.
Food stuff? Same thing. Ask the customs people. They will point you in the right direction.
Jim Straw also has a good book on Exporting from the US. And while it is technically for those in the US I feel its information applies to all western countries. (I've received goods from India and the documentation that it came with was virtually the same as what Jim's book shows you.)