You don’t state how long the road trip will be. I would recommend spending a night in each town if driving. You can make a loop to visit the towns and it really doesn’t matter which way you go, clockwise or counterclockwise. Assuming you pick up the car at the airport I’d visit Toledo, followed by Salamanca, and end up in Segovia. That would put you north of the airport for an easier return. There are some toll roads in that area, especially from Segovia back to Madrid. We avoided all of them on a recent trip by taking back roads but we weren’t on a tight schedule. Between Salamanca and Segovia you pretty much must pass by Ávila, so consider making a short stop to see the walls. Near Segovia is Coca castle if you like castles. En route back to Madrid is another castle, Castillo Manzanares el Real.
Google maps should give you no toll options if you use it. Gas (E95) was running about 1.85€ per liter ($6.80 a gallon at today’s exchange rate.)
In Toledo we stayed at Hotel María Cristina outside the historic center since it has its own parking garage. There is free parking in Toledo along Paseo de la Basílica. It’s on the side of town near the Roman Circus ruins.