Your Eurail pass gives you access to most of Europe's trains, but it's good to know that some trains need to be reserved in advance. A reservation is a guaranteed seat on a specific train.
We are now less than 75 days from departure on our trek through the Central/Eastern Europe. Our Eurail passes have arrived and now we are making seat reservations for the night trains that we will be traveling on. For the most part we will be using Couchette's and Seats. Our pass provides 1st class seating which really just means there is a bit more legroom.
As for figuring out which trips need to have reservations made? While here is one of the best resources that I have found along with seat61.com.
So, there you have it, we are still prepping the travel and have a good number of activities on our wishlist. Stay tuned and we will keep you updated.