Now that I think about it, I probably should have done this post at the very beginning of my Traveling in Europe series, but hopefully it will still be some help to someone out there.
I've had trip planning on the brain ever since Sean told me he wanted to take a long vacation. In all honesty, I constantly plan trips, even though we don't always take them. Trying to juggle going away at the spur of a moment with the military doesn't always work.
Anyway...I've majorly planned for our upcoming vacation. Normally I at least plan on what sights we want to see and get a few ideas of what there is to eat where we'll be staying. This trip I've gone all out. Because it is a long trip, with many destinations and flights, I've planned more than usual. I've done a Word document for each individual city with details like:
What time we get to the city
How to get to our accommodations from the airport
Name of hotel (hostel, etc) phone number and e-mail
Balance due for the room, whether breakfast is included
Sights we want to see, plus what the hours of operation are and what the cost is
I find it easier to break it down like that because I want to keep an eye on how much money we are spending and how much we can expect to spend on this particular trip.
Because we are flying on a budget airline, it means the size of our suitcase and weight allowance are pretty low. Because of this, I try to pack as light as possible. This means I don't want to haul 3 or 4 bulky guidebooks around. For instance, I have the full Spain and Germany guidebook. I only need the info for three cities in those guidebooks. So, I bought the Snapshot Guide for Madrid, Barcelona and Berlin. Much smaller and more compact and I don't feel like they are using up a bunch of extra space. (By the way I got mine on Amazon for much cheaper)

(See how much smaller they are?!)
I've mentioned that I use Rick Steves guidebooks and the site Tripadvisor, but I also have a few other recommendations for sources. The magazine Budget Travel is one of my favorites, I often go through my issues, tear out pages that I think we are interested in going to and then put the pages in plastic folders and into a large 3 ring binder. That way before a trip, I can just flip through it, see if anything applies to where we are going and add it to my planning. The website for Budget Travel magazine is also very helpful.

(My travel binder)
Another source I utilize is blogs. There are some great blogs out there that detail life in cities all over Europe and the rest of the world. Some are written by natives of that country or city and others are Ex-Pats that now consider that place their home. I have some helpful sites on the right side of my blog. Others I keep in an special folder under my Favorites tab. I just recently stumbled upon a blog from Rome that had great non-touristy recommendations for gelato and dinner.
I realize there are some people out there that don't like to plan and would rather fly by the seat of their pants when the travel. My husband is like that, I'm not. I think in the long run you end up paying more money when you don't plan you trip out. I know that firsthand from several trips that we've taken in the past.