How to do your (business) friends a solid when you don't have much to offer?

So I know it's pretty strange to ask this but I happen to have built relationships with some people around the world that I'm either likely to work together with or just be helpful to each other in the immediate and hopefully long-term future.

At the moment, I don't have a lot of things to offer them except when I come into some information that maybe helpful to them. 

How do I do these people a solid without crossing the ethical and cultural line? I'm particularly interested in what's appropriate in the US, UK, Western Europe, Singapore, and S. Korea. 

In the above countries ethical lines are very different - eg) in East Asia, gift giving (those fruit baskets and Johny Walkers man) is still totally a cool and encouraged thing to do but in the US that seems very "bribe-y". In the EU - it seems very country based and circumstantial. Like bringing a good bottle of wine is totally okay in France if it's a meal but don't bring like alcohol to the office in Germany? No idea about NL, UK, Portugal, Sweden, etc... Another example, how are hand-written notes or well-crafted emails perceived differently? Or how about book gifts with personal notes? It just confuses the hell out of me sometimes.

I know it sounds like I'm bragging but this is a real problem I have and if I don't manage it well, I feel like I'm gonna burn some bridge without knowing it because I didn't know how all these different bridges work. Thank you for your help.