Unfortunately, Dutch seems to take a back seat to German for some publishers of language learning products. And like it's cousins Danish, Swedish and Norwegian, there are noticably fewer products to choose from for those who want to study Dutch. Here are some of the easiest to find products for learning Dutch.
Internet/Free Learn Dutch at Taalthuis Your best bet for a free tutorial to learn Dutch. Well structured beginner and intermediate lessons with grammar, tests, basic vocabulary and pronunciation guides with sound files. There are also recommendations for further study and a maillist.
Dutch For Beginners
Another good site for Dutch beginners. Lots of grammar and basic vocabulary to get you started.
Internet/Free 2BDutch.nl This is a great site to supplement your other tutorials and learning methods. There are tons of videos in Dutch with subtitles on a wide variety of subjects, not to mention videos specifically for learning Dutch.
Teach Yourself Dutch
The longstanding Teach Yourself series has always had the widest variety of languages, and Dutch is no exception. The course has been renamed Complete Dutch (it still has the Teach Yourself label on it though), but it is essentially an updated version of the same course. The coursebook comes with two audio cd's and makes a good introduction to Dutch. It is inexpensive and is easy to find as it is available in most bookstores or online.
Book Teach Yourself Dutch (old version)
A great grammar based book is the old version of Teach Yourself Dutch. Published by David McKay Company or English Universities Press in the 50's, 60' and 70's, these old Teach Yourself books are great grammar-intensive workouts with lots of little exercises. Try this as an inexpensive but thorough grammar course, and get your updated audio elsewhere. They are out of print but can be found in used bookstores or online.
As far as ease of use and quality of the material and method, Pimsleur is the best. You learn to speak Dutch in a natural and comfortable way. Simon and Schuster has recently expanded their Dutch offering to include an Instant Conversation Dutch and a 30 lesson Dutch Comprehensive. Pimsleurs all-audio format is a great introduction to the language, and with it you'll develop a better accent and conversation ability than with any other published language method. It's a great way to begin to learn Dutch.
It is less popular than some other Pimsleur products (like Spanish, French etc) and can therefore be even more expensive than those other courses. Because it is only offered in Level 1 Comprehensive, I think it is a little short. Instant Conversation may be a more cost-effective choice if money is an issue.
Read my more indepth
Review of Pimsleur Products.
Transprent Dutch Premium uses native speaker audio, text, video, games and dialogues to immerse you in the Dutch language. With 15,000 words in mp3 format to use in your iPod or mp3 player and it can be fully integrated with BYKI. And, there is a six month guarantee. Overall, a great and affordable resource to learn Dutch!
Tell Me More Dutch
This is my new favorite language learning method! It's just the right mix of useful content, activities and games, dialogues, native speaker audio, video and more. It's a sophisticated and great-looking language program. The best part of Tell Me More Dutch is the amount of content for intermediate and advanced learners. It may be the most complete and comprehensive language program yet made. I highly recommend you see the online demo. This is an excellent method for learning Dutch!