I've got this routine pretty much down to a science, and even though style may change over time, this is quick and simple--perfect for blog photos. Read on for my personal tips!
Step 1: The first thing I do is stick my camera's SD card into my computer and copy over the files. I organize my pictures by month and year, but that's totally up to you. I just move the files, and when that's done, I immediately delete them from the SD card. This ensures that I always have maximum space for taking photos. I also pretty much always move and edit pictures right after taking them, so I don't get behind.
Step 2: I give all the pictures a once-over in +Google Picasa. I flip through them to delete any blurry ones, narrow down choices between similar shots, and fix any rotation problems using the "Straighten" tool. Hint: to mark your favorite photos as you sort them, hit the Spacebar and they'll get a gold star! If I've made any changes to the pictures, I hit the little "Save" icon under the folder name.
Step 3: Once I've weeded out all the rejects, I open GIMP. I click "Open" and then select 4-5 pictures that I want to work on, opening them all at once. They appear in little tabs above the image. Then I start working through them! For blog pictures/pictures that don't need much work, this is my routine: Duplicate the photo layer, and set that layer's mode to "Overlay." Then click "Colors" --> "Desaturate." Try out the options and pick one. Then I just export as a JPEG, exit out of that picture, and click "Close without saving" since I don't need the .xcf file. The end!
That's it! All of the programs I use are free...because college student...but they work great, in my opinion! All that's left to do is upload to the blog post!