I'm noticing a surprising number of readers for this post (in fact it's quite surprising when any of my posts get a hit) - so I'll take it upon myself to recommend further reading of the various Lewis Carroll biographies.
- If you're only going to read one: pick one of these three quite factual treatments: Derek Hudson is a solid treatment and probably the most 'popular' of all the ones I'll mention here, but rather old now. Michael Bakewell has a more modern perspective. Ann Clarke is in the same territory as Derek Hudson, but pays more attention to how Alice and Mrs Liddell might have perceived events, and as such might well appeal more to readers of this post.
- If you're ready to read widely: as well as the above bios, Donald Thomas and Morton N Cohen allow themselves to speculate more freely. If it came to a choice between those two I'd keep the MNC book, because it's more exhaustive, and also because MNC keeps Lewis Carroll centre stage when DT prefers to switch to covering late 20th century moral panics.