hp50g page on hpcalc.org website
Containing handy links to the official hp 50g manuals at the end of the page. Official user guide, advanced user reference and the quick training manuals.
Hp 15c Advanced functions handbook. Great exposition of advances functions (math disguised as a calculator manual) and how to consider precision errors (timeless observations) in calculators.
HP official
you will find there (in terms of discussions already done), numbers made up to give an idea: 75% more help on commands; 20% advanced RPL programming, 5% more advanced programming and math.
MoHPC forum
you will find there (in terms of discussions already done), numbers made up to give an idea: 20% more help on commands; 50% advanced rpn/RPL programming, 30% more advanced programming and math.
Newsgroup comp.sys.hp48
you will find there (in terms of discussions already done), numbers made up to give an idea: 30% more help on commands; 60% advanced rpn/RPL programming, 10% more advanced programming and math.