Sorry, no blog. The route idea came out of Bicycling Mexico, and Guia Roji was helpful. We also asked locally and the tourist office in Patzcuaro, for example, recommended that we take the new 2-lane toll road (a better road with less traffic, we were told) from there to Uruapan. We did, and that worked out well. We weren't expected to pay the tolls, and neither the tolltakers nor police objected to our being on that road. You just have to go around the sensors at the toll booths so the tolltakers don't get blamed or charged. BTW, biking around Lake Patzcuaro is especially nice. Very interesting villages, nice scenery, and not much traffic.
Since then (I think this trip was in 2002), I discovered INEGI maps, available in government offices in each Mexican state capital, several offices in Mexico City, and a small sales office in the Mexico City airport. They've got topographic lines, which are a big help. Any one INEGI office is typically out of many of the maps, which is frustrating. The maps were helpful when I spent some time on my bike in Chiapas last year. In places where there are new roads, they probably won't be on the INEGI maps yet. Guia Roji should have them, however.
Guadalajara is a big city, but it's nothing like Mexico City. However, we ended up taking a bus back into Guadalajara. Nevertheless, I rode around the city for about 3 days and it was fairly pleasant. The road to the long distance bus terminal to and from the center of town wasn't great, but it wasn't horrendous, either.