Hi tekgirlkix,
Check out Son of SNB Errata for a discussion about Lidsville.  Bower Bird used Inca by Patons; I'm not familiar with that yarn, and she found hers in Australia. I used a really cheap yarn called Fishermans Wool by Lion Brand from Joann's Fabric and Crafts and it came out OK.  The description of the yarn in the book is wrong: the skein should say 183 yards, not 18.  I'd think a worsted weight would work; I just bought Cascade Tweed in a lovely dark blue, and will try and make that work, once again by crocheting and measuring as I go.  I would think that basic Cascade 220 would work, too.  Tweed Cascade 220 is 4 1/2 sts per inch on #8 needles, so I'm going to try a swatch with the "I" hook, and if that's too big, try again with an "H' hook.  Varying hook size and tension can create a big difference in actual gauge.  
     My first problem was not crocheting a gauge swatch, but I used the gauge in the book and determined what size each piece should be, then obsessively measured each piece as I worked so that they would be the correct size.  The top piece took a couple of extra rows to get the correct length, and I ended up crocheting quite loosely to get the width/stitches to come out all right.   The inner band was a puzzle: from the gauge, it would be smaller than the specified head size, so I again added rows, which made it come out loose.  Bower Bird croched it to pattern and stretched it when crocheting it in place to give a snug fit; that is probably the correct way to do it.
   Good luck.  Let us know what yarn you end up using and how it comes out.    

Well, my first draft was too small so I remade it with a larger hook.  It turned out great!  The hook I used was one size larger than the suggested hook, and I DEFINITELY slip-stitched the pieces together.  Whip stitching doesn't give the the same structure effect.  I also had to stretch the inner band to fit it into place.  It's important that every stich of the band is attached to *every other* stitch of the hat.  That threw me a little.

And I also think it's important to note that the brim is attached along the outside edge of the brim piece, not the inside.