SEO does not stand still, and always something to change, supplement, it is clear.
And what sources can help you to learn about seo, and to read every day?
What can you tell?
Waiting for your comments.

I daily read SEO blogs for the latest updates like SEOmoz and seoroundtable.

For keeping an eye on your traffic analysis, subscribe to Google analytic blog and may be Yahoo web analytic.

For getting aware of new things in SEO, read Google webmaster central blog which keeps you updated about whats going on.

To study the detail techniques on how Google changes its search technique, subscribe to blog of Google INsight search.

When you find any single concept from above blogs, try to find how those concept can be used and you can read other private blogs to explore more on each concept.

Every search engine has its own dedicated blog which you can follow. In addition to it, you have these online resources (search engine watch, SEOMOZ, SEO book, search engine journal etc..) . Alternatively, you may follow all these on Twitter.

According to me Google is the best place to keep the knowledge in SEO. I read the Gmail Blog and Google Webmaster Central Blog to know about latest updates from Google. Following link will also helpful to know about latest updates of SEO.

www.seobesttips.com

Participate on SEO and Internet Forums and Blogs to learn new SEO strategies and tricks that are coming up.

Seomorz.org ie the best wasy to learn seo

I have best way for get SEO knowledge. Blurbpoint provide SEO guide it is amazing source for SEO knowledge. I am work as SEO executive last two years. But any time any problem in SEO I refer only  Blurbpoint SEO guide.