You're lucky to have someone so close to you who you can learn from.

As for editing images, it depends on a number of factors. I believe that you should always shoot in RAW format whenever possible. And RAW files taken straight out of a camera will always require some form of post processing.

I apply lens profile corrections, exposure, white balance, saturation, and contrast adjustments, to almost all of my images. I may also choose to selectively edit a certain part of an image if necessary. I'll never use Photoshop to add or take away a specific element of a shot.

If you're interested in watching me edit a photo, I uploaded a video at the bottom of this post - Editing With Phoblographer - Songbirds. If you watch it with sound, I talk through the different aspects of my edit.

I think subtlety is the key to good image editing, as is finding your own individual style. Anyway, let me know if you have any photography related questions in the future, and I'll do my best to help you out.