It's consistent to a point. There have been several revisions of The Hobbit and LOTR over the years, but all were done by JRR himself I believe, and were done f

It's consistent to a point. There have been several revisions of The Hobbit and LOTR over the years, but all were done by JRR himself I believe, and were done for continuity sake and detail. As far as the worldbuilding goes, it's exceptionally consistent. Considering the bulk of all work put out was done by JRR, with Christopher Tolkien doing editing passes during compilation. For instance, the Children of Hurin and The Lay of Beren and Luthien were described in LOTR and the Silmarillion, but were not included largely due to length and incompleteness (the Silmarillion is really just a Cliff's Notes version of the full Legendarium, allegedly). As far as a timeline goes, several are available, but I would try to steer away from most wiki sites, as they have been, in the eyes of some, 'polluted' by the handling of the IP by non-Tolkiens. (ie the movies and games like Shadow of Mordor) Geography of Middle Earth is a somewhat complex topic, but the big deal is that it goes through some drastic changes as part of the Silmarillion called the War of Wrath. Other than that large shift, the geography is very consistent. Tolkien really, really loves his maps.