Right! First thing to do is install a dutch/english dictionary on your computer:
http://www.travlang.com/Ergane/
It contains 15.000 words. You can also access a (slightly better) dictionary through Internet on: http://www.taalthuis.com/wb.html

Then you'll need a Dutch course. There's an online course on this site here (this link is easy to print), but you can also start at  http://www.blue.demon.nl/dutch/main.htm.  I added the vocabulary of the online course (this link is easy to print) in here.

There's a useful small dictionary that you can print and use as a vocabulary at:
http://www.draak.demon.co.uk/dutch/en-nlc.html and at
http://www.pagesz.net/~graysonm/languages/dutch_dict.html
A good online grammar site is to be found at:
http://www.draak.demon.co.uk/dutch/

Practise, practise, practise! The following pages contain lot of tests for your mastering of dutch:
http://www.wins.uva.nl/cgi-bin/learndutch.CGI  (online words)
http://ourworld.compuserve.com/homepages/Joschu/en.htm (fill in tests)

Then, just to fill in the necessary gaps, you can find a slang dictionary in here:
http://www.notam.uio.no/~hcholm/altlang/ht/Dutch.html

If you need peer support  of other dutch pupils you can find them on the mailing list of taalthuis:
http://taalthuis.com/d4e/  (dutch four english)
It's a kind of study center at:
http://taalthuis.com/

Maybe practical is the dutch for travelers site with online translation of sentences for
travelers at:
http://www.travlang.com/languages/cgi-bin/langchoice.cgi?page=main&lang1=english&lang2=dutch