Mainly the sort of information I'm doing for all the generations is stuff like info on the starter Pokemon, recommendations for good party Pokemon, tips on beating the Gym Leaders and Elite 4, differences between the base pair and the 3rd versions (or in the case of the remakes, them and their originals). Have a few other things in there too, like for example for R/S/E I have a bit on getting the Regis.
CodeHelmet has already provided a bit for differences between R/B/Y and FRLG, so that means that stuff like party recommendations and gym leaders still needs to be done, assuming that there's enough different that what was good/what worked in the originals needs updating for the remakes. Probably need stuff on the Sevii Islands too. Or whatever you wanna write about, I'll take whatever I can get at this point.