http://www.seat61.com/
This site with a bit of browsing should give you the answers you are looking for.
Remember within Europe there are in effect two main types of trains: The expensive, very fast, (150-200mph) express trains which go under different names in each country, TGV, InterCity, ICE, EuroStar etc these tend not to take bikes (unless in a package less than a certain size, like aircraft packaging)
And then there is the normal service which is slower (50-120 mph), stops more often, has more restrictions (typically no rush hour travel), but is usually equipped for bikes.
Also keep in mind Europe is not a single country (yet...), there is no single rail system, no single language, no single currency, therefore cross border travel involves a degree of challenge, but that is all part of the adventure.
And by the way a Eurorail pass is valid all over the European Union and even some countries outside, but not, however valid in the UK.