we haven't been in a while, but here's the things I had for Mexico
Check Latitude 38 for their "First Timer's Guide to Mexico". They run a rally every year in November (the BajaHaHa) so usually have the most up-to-date information on ever changing formalities. The rest of that guide is only moderately useful to someone who has already spent time cruising.
We used Rains' Mexico Boating
Guide and found it quite useful if a bit expensive.
I have always liked Charlie's Charts
and they do a Mexico guide, but I fear they are probably somewhat out of date. Haven't looked at a recent one for Mexico, but that is what I have found in other regions.
Don't know of any guides a la Soggy Paws but maybe someone else will jump in.
When you get to Panama
the Bauhaus guide seems to be the standard but you may already have that one? For the rest of central America it's been too long to recommend anything.
If you're in Alaska
next summer PM me, too much to see up here.