The easiest way I have found is at http://circle.stylemepretty.com/ They have a lovely gallery you can pull from, clear guidelines and a easy drag and drop, grid system. Best of all, you can embed the code for any board into you blog.
I use photoshop to do my inspiration boards for the blog. (http://blog.shinyorb.com) Although it is more complicated, I find that there are a couple of big benefits:
1. I can make each picture clickable and link to a corresponding webpage. This is especially useful if you do not own the image yourself and it makes it easy for the reader to figure out what you're featuring immediately without looking through a list in your caption.
2. I can tag the photos optimally for SEO purposes.
3. I have finer control over placement and image resizing in order to design my own template.
If you want some step by steps, you can email me or google for how to make image maps in photoshop.
You are so kind Shiny, I appreciated it, although I have no experience in Photoshop. I did a few things in the past but totally different from inspiration boards.
I tried already Bridal Canvas, which Christine proposed, and I found it easy and very helpful.
I may be biased, eh um, as I am the blogger for The Dessy Group (www.dessy.com), but I think their inspiration board platform (http://www.dessy.com/PANTONE) is the best! You can choose from all of the Pantone Colors, use professional photography gallery, and also view other brides inspiration boards in the gallery (http://www.dessy.com/pantone/gallery/) to get inspiration.
Hi...I thought I would chime in. Everything everyone has stated, I agreed upon; however, no one addressed the creative side of creating the board. So if you want some hints on that I'd be happy to share my "pearls" on creating boards. I use Style me Pretty & Brida Canvas, too,