Growing Vegetables West of the Cascades by Steve Solomon is a great reference.

Solomon's book probably has all of the information you need, and he lived in Williamette Valley when he wrote it, so it's probably pretty accurate for your area. But it can be a little troublesome at times to find specific bits of information you might be looking for in that book.

If you want a month by month guide, tables, and other condensed, easy to find information, maybe "Seattle Tilth's Maritime Northwest Garden Guide" might be what you want. However, this book may too local to western Washington to be accurate for Eugene. Is Eugene considered to be "maritime pacific northwest"?

http://www.seattletilth.org/about/books-for-sale

OP wrote: However the information was rather limited and the regional tips didn't cover the Willamette Valley."

Umm. Yes, it is limited,. That's because you'll find much more in the various OSU publications, the majority of which are online.

And yes, it does have tips for the Valley. The Valley is Region 2 in the planting chart/map.

Beyond that, you can obtain lots of appropriate info in OSU Publications at http://extension.oregonstate.edu/catalog/results.php?cat=Gardening.

Also OSU monthly garden calendars at http://extension.oregonstate.edu/gardening/calendar/.

These links & more are on the OSU Gardening Encyclopedia website at
http://extension.oregonstate.edu/gardening/

Here is a link that might be useful: OSU Gardening Encyclopedia

Then, too, you'll receive personal attention when you call the Master Gardeners in Lane County. Look here http://extension.oregonstate.edu/lane/gardens

Here is a link that might be useful: Lane County, OR, Extension Service

>you'll receive personal attention when you call the Master Gardeners in Lane CountyAre they cute?