Which book

For Budapest I might be inclined to use Ricks books to plan, but carry the Eyewitness Top Ten Guide. More user friendly on the steet, great map included and very small and compact.

Best time to find out if the guide books overlap is at home. Read them before you go. If unsure about buying spend some time in the book store or the public library.

The Eastern Europe book has adequate information for both cities, and presumably covers other cities in your itinerary. The additional information in the Budapest and Prague "city guides" includes:

• A number of self-guided walking-tour and museum-visit routes in the big city.
• More side trips and destinations outside those main cities. They're closer to being guides to their respective countries, but still more selective than comprehensive.

See more "What's Included" info for each at https://store.ricksteves.com/shop/guidebooks/eastern-europe.

I like DK or Insight Guides for planning. They show (IMHO) everything , I use RS for self guided tours, restaurants, accurate opening/closing times, best ways to get around etc. If you are spending all of your time in Prague and Budapest, I would stick with the city books, if spreading out a bit more, the Eastern Europe book is likely enough. However, my own law is: when taking a $5-6,000 trip, don't skimp on a $20 guidebook. After all, if it saves you an hour or two, is has generally paid for itself. So I look at DK or Insight Guides at home to strategically plan, peruse, get ideas etc. Then I take RS guides on the trip to pick hotels, nearby restaurants, museum times and so forth when I am actually in the city.

Ray, we are talking about the same guide. It comes in the full version which is excellent for research and the Top 10 version which is great for the back pocket or purse. They don't have as much data as the RS books, but they are more visual with excellent 3D maps of small areas of interest. http://www.amazon.com/gp/aw/s/ref=is_s?k=dk+budapest

Fully support what James said. I have a number of DK "Top 10" guides but a lot more of their "full" guides. The pictures, descriptions and broad coverage make the "full" guides invaluable for research for me (similar to the Insight Guides [published by a different company], although I prefer DK.) DK also makes a few pocket maps and guides-I have ones for St. Petersburg and Moscow.) While I love them at home, I take the old razor knife to RS and only take the sections I will use with me on that trip. While I keep the DK guides for future reference, I count on RS for better "up to date" info on hotels, opening hours, what museums are being remodeled etc. So when returning to an area, I will re-read the old DK guide, but purchase a new RS guide.