I would say learn manual first to understand how the aperture, shutter speed, and ISO work together to get exposure. Auto mode doesn't know if you want to freeze motion, if you're taking a landscape shot and want the lens at it's sweet spot for maximum sharpness, or if you're taking a portrait and want to blur the background. Of course they're are times to go with full auto if you see a shot and don't have anytime but to flick the switch and fire. I would say learn manual first and then learn shutter and aperture priority modes. For example I'm learning shoot birds with my 100-300mm lens so I use shutter priority and set the ISO to auto with maximum of 3200...so the camera will automatically select my aperture & pick and ISO between 200-3200. This way I only have to pick the appropriate shutter speed and do my best to get focus and take the picture.
...that is what the various scene modes are for. Jason is absolutely correct, the camera does not know what you want to do, but the scene modes are designed to help in that.
Portrait, e-Portrait, Landscape, Landscape + Portrait, Sport, Night, Night + Portrait, Children, High Key, Low Key, DIS mode, Macro, Nature Macro, Candle, Sunset, Documents, Panorama, Fireworks, Beach & Snow.
These modes optimize the auto program for these situations...experiment with them, and what they do, and you can replicate some of these settings in the P, A, S, and M modes, and develop your own styles. But if you are in a pinch, these scene modes can be very helpful to you...many will scoff at this recommendation, but it is another way to learn, and understand the Olympus approach to many different situations...which can ultimately help you make better pictures.
Your camera is really a camera combined with a very sophisticated computer, and these are akin to different photo situation apps.
This book I recommended discusses this in more detail, and has a page per typical photo situation an amatuer is likely to come across, and how to use PASM modes or Scene Modes to help you take better photos.
Take the Shots that Make Jaws Drop by Steve Canale
The book is not an end all solution, but it rapidly allows a novice to figure out what direction to go in when coming across typical photo situations...If you can spend 20 minutes playing with each situation, it will help you understand your camera settings so much better, and give you a foundation for moving forward with less frustration. This is really one of the few practical books I have come across that is not too complicated and not too voluminous. It is the size of a notepad, hence my previous recommendation of spiral binding it and sticking it your camera bag.