In a News item on 25/02/07 - Looking for jazz chords, Barrie Marshall recommended trying :-
John Muskett has checked it out and has offered his comments and in some cases, preferred alternatives.
Just to put in my two penn'orth over the Vanilla Chordbook. It's often easier to identify a wrong chord than a right one, and it doesn't usually pay to be dogmatic... a different version from a reputable source is likely to come along and bite you on the leg. So....
Good Points: good selection of tunes, clear presentation, keys usually as published, wise introduction, chords generally reliable, chords kept simple to allow the harmonic path to be discerned, "April In Paris" chords as sensible as any.
Bad Points: no verses, no composer attribution, some "definitely" wrong chords, e. g. bar 13 in Alexander's Ragtime Band should be /C: C. Cdim/, bar 28 in "There Will Never Be Another You" should be /Cm7: F7/; several middle eights with dubious sequences (Anything Goes, I'm Getting Sentimental Over You, You Brought A New Kind Of Love To Me); several titles incorrect: (I'll Take) Manhattan, (In My) Solitude.
The simplicity occasionally obscures some passing harmonies which could be of interest, particularly to pianists, guitarists, bassists.
Some keys, while being the "published" ones, are not the keys used in the composers' recordings: Ellington's music suffers from this (Mood Indigo, Solitude, It Don't Mean A Thing, I Got It Bad..., Do Nothing Till You Hear From Me).
Overall the good points outweigh the bad ones; I would say use with care (there are at least two horrendously inaccurate chord compilations in circulation). No source is 100% reliable - I'm forever amending (and expanding) my own collection.
My own preferences for trying to establish reliable sequences are contemporary piano copies for Tin Pan Alley/Show Tunes, and earliest recordings (Red Hot Jazz is most useful - terrific collection of 20s music) for tunes composed by (jazz) musicians. Books of tunes sometimes include re-harmonised versions, and should be treated with suspicion. e-bay and Travis and Emery of Cecil Court, London have been sources of old sheet music for me. The British Library has many tunes of interest, but joining/researching/ordering is a ball-aching process, and you can only look (& make your own notes - in pencil!). If anyone wants to discuss any tunes with me, my phone number is in the MU directory.