First up, if you are planning a destination wedding like I am, sign up for an account at Best Destination Wedding. It's chock full of all sorts of information you could ever need, and in some cases you'll find out stuff that you didn't even know you were looking for but are so glad you found. Trust me. The forum also is worth signing up for. There you can chat with other brides from all over the world who are sometimes dealing with the same issues you are with vendors overseas. They are all super friendly and more than willing to help out. Plus, you'll pick up so many great ideas from other brides! It's a wonderful tool and I for one am so grateful it exists.
Next, I don't know what I'd do without Project Wedding. It's a fantastic source of inspiration for brides-to-be; it's also a great place to find some DIY project ideas to personalize your wedding. Even if you're not a crafty bride (like me), you'll be sure to find something that you are willing and able to tackle. Also, if you sign up for an account, you'll receive an email a day with your wedding countdown and an article for you to read.
I also really enjoy browsing through Wedding Bells for articles and inspiration. They have a great wedding planner tool which is very easy to use and super helpful. Plus they're always running contest with awesome prizes =)
Another great site for articles and inspiration is The Knot. They even have this fun feature called 'My Inner Bride' where you can do a mock up of yourself in different styles of wedding dresses. Here's one I did for fun:
These are just some of the tools I've been using to plan my wedding; there are many, many more out there that I just can't remember! What are your favorites?