^That's a really hard thing to define. Probably the best place to start in regards to a "starting point", the closest thing I would say to one would be the Avatar
duology, the start of the post-finale DS9 books or maybe even the SCE.
But realize that New Frontier, Stargazer and SCE all actually pre-date the DS9-R in terms of release date. Also, the TNG novel Diplomatic Implausibilty pre-dated Avatar but provided foreshadowing for the DS9-R.