I'm new to this too, having just started about two weeks ago. There is a Web page on the Legacy site that gives a different (but quite similar) approach to the one recommended here:http://www.legacyfamilytree.com/SourceCensus.asp
It might be worthwhile looking at it.
Funny, but to me (a definite newcomer) it would seem more effective if the master source would simply be something like: "1910 Federal Census" with the specifics (county, state, roll number, etc., etc.) being placed in the detail source. That would keep the number of master sources down to a manageable level. However, since people who have more experience seem to do it with a different master source for each census year and each county, I plan to do it that way too. Just speculating, but perhaps doing it "my way" requires too much variety of information in the detail source.
Perhaps someone can address this issue.