Since there's more to making a photo great then just the camera, we look to software options like Adobe Photoshop or Apple's Aperture to add post processing or effects to our images. Generally these software packages cost a bit more than a general hobbyist can afford, but thanks to the growing number of great free web apps that cater to the beginner even those new to photography can develop their photographers tool kit.
PicMonkey (Chrome, Firefox, Safari)
iPiccy (Chrome, Firefox, Safari)Aviary Image Editor or Pixlr, without simply mimicking the Photoshop interface so as to keep the learning curve a bit less steep for newcomers.
Pixlr Express (Chrome, Firefox, Safari)Pixlr, this app is by far the one of the more attractive browser apps I've used. With a simple to use interface that looks great in fullscreen, and offering a subtle yet smart selection of basic tools and features, Pixlr Express takes photo editing for beginners a step in the right direction. Though missing some expected pro features such as curves and levels the interface really makes up for what it lacks in feature depth.
Though there is no real substitute for pro level software, a steep learning curve often leaves hobbyist out of the loop. These browser apps offer a stepping stone into a more intermediate photography workflow helping newcomers find their footing with the vocabulary and tools of trade. If you're just getting started with photography, or even if you're a seasoned pro who wants to diversify their tool kit, these simple to use (and more importantly free to use) browser apps are definitely worth checking out.