A few websites to keep handy:
1. At the very beginning, open an account with TripIt. It allows for tracking reservations, tickets and schedules by emailing them in and then viewing them online from anywhere, even when on the road, in Europe.
2. Plan your trip using an online map site, like Google Maps. An alternative to it is ViaMichelin, my personal favorite. It is in my opinion, more flexible, allowing choosing directions by the type of desired route: Recommended, Quickest, Shortest, Sightseeing and Economical. Just like Google Maps, it allows bookmarking trips, which can later be imported into TripIt.
3. When it is time to spend some money, it is best to spend as little as possible. First, the airfare, there are two options: Lufthansa offers 2-for-1 tickets, so during high season, it is most often the best option. Second ticket is free, only taxes and airport fees must be paid. Also, when booking with Lufthansa, using the promotion, the production number must be supplied and only 30 days before the departure the ticket will be issued and credit card charged.
The alternative is an aggregate fare search like Kayak. It searches through tens of websites, both wholesalers and individual airlines to find the best price. Highly recommended! All the reservations received can be forwarded to TripIt so they will be added nicely to the itinerary.
4. Now, that the groundwork is laid, tickets purchased, European Delivery scheduled, it is time to add some more content to the trip. Here are some websites: BMW own website with a section on European Delivery trips, Wikitravel is another favorite with facts and tips useful when traveling. Another one is TripAdvisor, an enormous community of travelers. Great source of information and subjective opinions, which sometimes need to be taken with a grain of salt.
It is just a beginning and a starting list of websites, I will be adding to it as the date gets near.