The Polyglot Project, a collection of language learning tips from polyglots and language enthusiasts across the globe (including yours truly), is now available as both a physical book on Amazon and as a free PDF download. This tome of language awesomeness contains over 500 pages of language learning goodness from 43 authors!
When I started my Vietnamese intensive course, a lot of non-linguistists I talked to said that the Chinese students would have an advantage because they already speak a tonal language. It is true that some westerns could be completely stumped by tones, and just not get the language at all. But, a person who already speaks a tonal language does not have an advantage over a westerner or a Korean or Japanese who is intelligent, motivated and who is trying to learn tones.