Probably a BTCPay server guide, a link an inbound liquidity service (probably LNBig) and maybe if you have it maybe an LSP integration guide (I know breez has an SDK but do they have a BTCPay server plug-in? Seems like a missed opportunity if they don't). Along with some plug-ins I've seen to integrate with quickbooks maybe a link to satoshi pacioli accounting (https://satoshipacioli.com/about-us/)

Put a different way, I would gather resources I know are useful to questions I get a lot and shove them into a folder marked with what its for then copy and paste the contents.

You can see this style of organizing information on the "Bitcoin SOP" Github repo I made: https://github.com/nerd2ninja/bitcoin-sop

And yeah its a little messy. Maybe you like Lopps way of doing it better: https://www.lopp.net/bitcoin-information.html

Alternatively, you could give your consultation fee rates and take the job.