Some general tips
I've learned nearly everything I know from the following sources. Some day when I have time I may try to write out some more indepth suggestions. For right now, I provide you with the suggestions that got me started, and a few things I've come across on the way.
Wear out your camera - take as many pictures as possible, and then edit and review them. This is your most powerful learning technique which allow you to develop your interest, skills, and style.
Try to convey an emotion in your images. Think about the story or feeling you would like to convey, and then make sure that everything in your photos supports that. You may need to come back at a different time of day, a different season, or under alternate weather conditions - that's part of the game. Try to make your image have sound, taste, and smell, despite it being a purely visual language.
Wherever you are, there will always be something unique about that moment. It usually pays off to emphasize that unique feature and use it to your advantage.
Wide angle landscape photography can be very rewarding, but it can also be very difficult to compose with an ultra-wide (16-28mm on a full frame camera). Think of the focal length as a balance between foreground and background - the more you zoom in, the closer in size the foreground and background, as you zoom out the foreground becomes increasingly emphasized. I generally try two approaches: zoom all the way out, then start zooming in and moving around. Every time you zoom in, change your perspective until everything that was important to you is still in the picture, once you can't zoom in anymore, you've reached your proper focal length. This helps ensure that you have removed the less important aspects, and emphasized the important ones. Alternatively, you can embrace the wide view, and try to put as much exciting material in the photo, this takes a lot of experimentation, as small adjustments with such a wide lens will produce dramatically different results.
Color Enhancement
For natural, brilliant, clear and non destructive color enhancement I've settled on the following as my favorite:
Process your RAW image in ACR with roughly 15% vibrance, 10% saturation, essentially you want a relatively dull image, but not too dull. Then open the file in photoshop (if using jpeg you can just open it into photoshop).
Go to the layers menu, choose "New Layer Adjustment", and select channel mixer.
There will be three channels: Red, Green, and Blue.
For each of those channels change the 100% to 140% and the other 0%'s to -20%.
Don't touch the constant (this essentially changes the color balance).
Hit Okay.
Set blend mode - that's the drop down menu above your layers - to 'color'
Adjust opacity to taste.
Sharpening for the Web
This is a simple method for getting tack sharp images at low resolutions. I only outline the basics, you can extend what you know to further enhance this method.
Flatten your image in photoshop, resize it to twice the number of pixels you want to have in the longest dimension (ie. if you want your image to have 800px in the longest dimension, resize that dimension to 1600 pixels). Apply 2 or more sharpening layers with very strong sharpening - the image should look way to sharpened, terrible in fact. Resize the image to the desired size (ie. 800 pixels), whatever your preferred web display size is. This sharpens the detail while it's still there, as opposed to sharpening after resizing all the way down to web size. After you've resized to the web size, you can adjust the opacity taste, or even apply layer masks to selectively do some further careful sharpening.
For the sharpening layers you could for example do the following:
1. Duplicate the original layer, apply unsharp mask at roughly 0.3 radius, 500%, set the blend mode for this layer to luminosity. Note, since you're doing this as a mask, it's easier to use the opacity slider to control the amount, so use 500%.
2. Duplicate the original layer, put this new layer above the unsharp mask layer, go to filters->other->highpass, a radius around 0.2-0.6 should work. Hit okay, then set the blend mode to overlay. Now desatureate that layer using hue/saturation (we don't want to change colors). Now create a contrast adjustment layer, and when the dialogue pops up, select "Use previous layer to create clipping mask". Then put a point on the curve dead center, and then bring the shadows and highlights portions in so that they just barely span the peak - this increases the effect of the highpass.
And now, some links: The bold links are ones I find particularly useful.
The Basics:
http://www.uscoles.com/fstop.htm
Photoshop Tutorials:
http://www.ronbigelow.com/articles/articles.htm
http://www.luminous-landscape.com/
http://goodlight.us/writing/tutorials.html
http://www.theradiantvista.com/
http://revision3.com/pixelperfect/
http://www.photoshopusertv.com/
http://www.russellbrown.com/tips_tech.html
Cleaning Digital Sensors:
http://www.cleaningdigitalcameras.com/index.html
General Articles:
http://www.naturescapes.net/docs/index.php/articles
Digital Sensor Analysis:
http://www.clarkvision.com/imagedetail/digital.sensor.performance.summary/
Bird Related Links:
http://www.birds.cornell.edu/AllAboutBirds/
http://www.birdsasart.com/
Useful forums for technical questions and photo critiques:
http://www.fredmiranda.com/
http://www.naturescapes.net/
Photography Equipment Reviews:
http://www.fredmiranda.com/
http://www.dpreview.com/
http://www.photozone.de/
Canon: http://www.the-digital-picture.com/Reviews/
Which Tripod?: http://www.bythom.com/support.htm
Filters: http://singhray.blogspot.com/
Shooting Panoramas:
http://www.panoguide.com
http://www.panoramas.dk/
http://www.autopano.net
Buying Gear:
Used: http://www.fredmiranda.com/forum/board/10
New: http://www.bhphotovideo.com/