Scanning, Faxing & Copying

I have a Laserjet Tank 2604sdw which has an automatic document feeder. The printed documentation for scanning is very superficial. I have several questions:

--Is there better documentation somewhere online ? If so, what is the URL?

--There is the HP Smart software, but when I look at the support page of the printer there is also something called "HP Universal scan" and "HP print and scan doctor" and "Firmware controller" and "EasyStart printer setup". The support page has no explanation of what each does or how they differ from each other. Are these documented somewhere? If so, where? If not, what are they and which ones should I install to make full use of the printer (and especially the scanner)?

--I have installed only the HP Smart software. When I go to scan I get a series of undocumented options. Some seem clear, like "photo". But others are unclear. What do these do: "batch", "text extract", and "book"? If there is documentation somewhere, please give me the URL.

--The scanner does not do 2-sided scans. How do I scan a multipage document which is double-sided using the scanner?

--I have some documents that are A4; others are 8.5x11. Is there a way to set up 2 shortcuts to tell the scanner which kind of page I am scanning?

Thanks for your help.