Improving Photos for the Web (Adobe Photoshop)

1. Full screen
2. Levels and/or Image | Adjustments | Shadow/Highlight (click on Background first)
3. Brightness / Contrast
4. Hue / Saturation
5. Filter | Sharpen (click on Background first)

Sizing Photos for the Web (Adobe Photoshop)

1. Open the fill-size image
2. Image | Image Size
3. Change the resolution to 72 pixels/inch
4. File | Save As | rename file with _72.jpg

Creating a Thumbnail for the Web (Adobe Photoshop)

1. Open the _72 image
2. Image | Image Size
3. Change the widest dimension (height or width) to 1 inch
4. File | Save As | rename file with _t.jpg

On your phone, try Snapseed!

Scanning

1. Scan at 300 dpi
2. Rename the photo
3. Edit in Adobe Photoshop as appropriate
4. Image | Image Size (72dpi, set size)
5. File | Save for Web