I'll only address Toledo (I have not been to Montserrat).
First, I see no need for any sort of guide when visiting Toledo. The city is easy to navigate, major sites are not hard to find, and the city itself is actually the major draw.
Toledo looks like the perfect day trip: it's a quick, easy bus or train ride from Madrid. That's why vast throngs of people go to Toledo, as a day trip, from Madrid. And that - because virtually everyone does Toledo as a day trip - is why doing Toledo as a day trip is a mistake.
Toledo is very popular. It's crowded - very crowded - mid day. There are too many people crammed into its streets from 10 am to 4 pm, and IMHO that ruins the experience. But after 4 pm and before 10 am, the place is empty, magical, and a lovely, wonderful experience.
So all you have to do to turn a bad experience into a great one, is to invert your scheduled time there: don't go mid-day, go outside of those hours. Arrive mid-afternoon (say, 3-4 pm), enjoy the wonderful old city free of crowds into the evening, spend the night in the old city center, get up early, enjoy a few more hours in the morning, then head back to Madrid around 10 am, as you watch the city streets fill up and overflow with tour group crowds.
True story: a relative took his family to Spain. Before the trip, he asked me for advice. I gave him the above advice for Toledo, he said he would follow it. After he got back, I asked about his trip...
Him: "Spain was great, you were right!"
Me: "How did you like Toledo?"
Him: "Oh, it was awful. It was so crowded - we hated it!"
Me: "Really? And you spent the night there?"
Him: "Oh, no - we wanted to save a few bucks by sleeping in Madrid - we did Toledo as a day trip...but I wouldn't go there again."
Me: Falcepalm...