GAAP, partnership, audited financials. Knowing the specific industry may also be helpful if there are specific guides for it.
Fwiw, I use only the guides from PPC (Practitioner Publishing Co) through Thomson Reuters. If looking at its products, I'd start with the guide called "Preparing Financial Statements" that goes through each major item on each statement and has a chapter on disclosures that includes summary and comprehensive checklists of required disclosures, either in the statements themselves or in the notes. The appendix to that chapter also has some illustrative notes. PPC also has a "Trends" volume that I believe is also included with this particular publication that has complete financials submitted by practitioners that includes the notes. The index to that guide allows the user to look up examples of individual notes by subject also.
PPC guides are the only ones I've ever used, and I'm sure other publishers of reference materials will have something along similar lines, including WK/CCH, and the AICPA.
PPC non-subscription products have a 30-day satisfaction guarantee. Those on recurring subscription have a different cancellation policy.