Maps

I love maps.  There's something finite and logical about a map, whether it's a sketch on a napkin, a USGS topo map of the back country, Google Maps street maps, or a GIS interface to plumb the mysteries of the municipal world.

And for cycling, maps open a way to plan routes of your own instead of relying on a rides book or website.
These are great starting points, and are still the best way to start out - especially if you are visiting a new area and don't have a guide.  A good ride book can give you not only the map itself, but will also tell you about that diner tucked in the back of the gas station on the corner of Cty 182 and SR 46  that's escaped all the hipster postings and TV shows.  In the present, there are a number of sites like "Map My Ride", Strava, "Ride with GPS" and others that allow you to post or download rides that others have done, plan your own, and even compete against other riders.  Some are free, and some are not.  The problem with most of these is that you can't readily tell the difference between a paved road with traffic, no traffic, shoulders, dropoffs, pavement quality or road surface in general. You are at the mercy of whomever decided that this was a good route for bicycles.  There are signed bike routes almost everywhere that defy explanation - crappy pavement, high traffic or abundant stop signs, when two streets or two miles over is an alternate route that has none of the problems listed.  So the trick in ride planning is to identify and avoid these 'features' in an area with which you may have only a passive knowledge.

I do a lot of ride planning for a group of friends on our Sunday rides.  Most of them are less enamored with maps than I am, and are happy to have someone else pick the route.  If it's scenic and low traffic, everyone's happy.  I live in the Minneapolis area, but due to traffic we do most of our weekend riding over in the River Falls, Wisconsin area.  With a little work, we can do 30-100 mile rides that are low/no traffic, decent pavement, a few climbs, and great pastoral scenery.  Pavement is generally pretty good due to Wisconsin's farm to market road laws that were intended to insure dairy farmers could get their milk picked up easily.
Another big help is that Wisconsin has a county-by-county map collection of road conditions, and their suitability for biking.  I don't always agree with them, but it's a darn good starting place.  Knowing what roads are probably paved is a big help when putting together a road ride - or finding likely suspects for a gravel ride.  I also use Google Maps, both map and Satellite view to drill in and verify likely road surfaces on roads that I don't know.  With a little practice, you can usually tell if a road is paved or gravel, and sometimes the pavement condition - but not always!  Sometimes you get surprised by road construction and just have to gut it out.
My route mapping tool of choice is a website called "Bike Route Toaster".  I've found it pretty easy to use, generates good turn lists, and with the latest update allows you to pick from Open Street Maps or Mapquest. It used to directly use Google Maps, but a change to the Google Maps interface apparently made them drop that option.

The process I use for designing a new route is pretty straightforward. A lot of it is based on experience, who is likely to be riding, and even anticipated weather - it's no fun to be 40 miles from the car when the bottom falls out of the sky.
I'll generally start with an idea like "I want to map 60 miles with a 40mi cutoff".  Then pick a starting location, and maybe a general direction depending on the factors above.  At this point, I'll typically pull up Google Maps(GMaps), and get a sense of major highways to avoid, available secondary roads, and maybe form a mental sketch of a route. At that point, it's over to BikeRouteToaster (BRT) to lay down a sketch.  I'll normally do this without really looking too closely at the actual roads - more relying on it to keep me out of dead ends, dirt roads and highways. Once I have an idea about the mileage, I'll go back and look at each segment of the route, comparing roads with the county map for traffic and surface, and back to GMaps satellite view for a final look at any suspect roads.  I'll also check the turn list to make sure we haven't accidentally done a left turn by making 3 rights, or overshot an intersection and doubled back.
It usually takes 3 or 4 iterations with BRT before I have the route I want.  When I do, I'll generate the turn list and GPX file for download to GPS units.
In the next couple of weeks, I'll start sharing some of these rides here under the 'Rides' page (on the right).  Feel free to use them, comment on them or suggest additions.

Enjoy!