Have a look here
http://www.saxontheweb.net/Rock_n_Roll/
Neil Sharpe has compiled a great resource of lessons and articles for anyone wanting to get their blues together.
Knowing your scales and chords is a necessary step, but in and of itself, I don't think that will help you blow the blues. As suggested above, you need to learn some vocabulary.
Grab some "loop and slow down" software, such as audacity, and transcribe and learn one generic blues solo. Just one chorus will get you going. But learn it so that you can play it inside out and backwards, in every key.
Most of us screw ourselves up by jumping onto the next thing before we've really absorbed what we are currently working on. Be patient with yourself. In 6 months time, if you have just a few blues solos down cold, you'll be able to mix and match them and you'll be well on your way to playing the blues.
In fact, if you find transcriping blues solos too difficult, just learn blues heads. If you pick a dozen blues heads and learn them cold in every key, you'll have more than enough vocabulary to mix and match them and solo convincingly. You'll also find that learning vocabulary makes learning vocabulary easier.
What I mean, is that the more you do it, the easier it gets. The first few take ages but then things start to click into place and you'll learn and remember it all with greater ease.
The blues has a vocabulary. Just running patterns on scales might at times sound something like the blues but it won't sound authentic. Learn the tunes and save yourself all that time trying to reinvent the wheel.
Good luck.