Coupla things:
I know Amir was not suggesting front light (sun behind the photographer) as an in-stone rule. What's good for birds is not necessarily good for a face. I would suggest that for people anyway, this if often not the best way to go. Hard sunlight often looks better used to backlight people -- that's how you get the bright rim that defines shape, hair, etc. -- that sometimes golden glow -- that separates people from the background. That bright sunlight is often not flattering on faces, and skin tone is often better a bit underlit, meaning not at exposure. The trick then is to expose properly for the flesh tone, and this comes down to understanding what you want to expose for and the metering pattern of your camera (often selectable). A little subtle fill flash can be very helpful here. You will see in so many movies and outdoor stills of models that they are down in brightness vs. the background. This comes from how the subject is placed vs. the light source (usually the sun) and whether overhead diffusive materials are used to cut the sun on the subject, letting everything outside of the covered area go brighter.
It may be that the difference between the brightest highlights -- in the hair, on the shoulders, the window curtain, etc. and the fleshtone exceeds the dynamic range that your camera can handle. It's OK to let the highlights burn in this scenario, particularly if you're not going to spend much time post-processing you image.
When shooting landscapes, the light right behind you is often the worst place in that it flattens out the textures and topography that can make for a striking image. As a simple tip, your best shots will usually come early morning/late day, particularly for landscapes, when the light is most angular and soft because it's passing thru more atmosphere.
Another tip is to learn the impact of focal length. Rather than standing in a spot and zooming to the frame you want, experiment by shooting the same frame from very different focal lengths , perhaps both ends of your zoom. Wider angle lenses/settings present a very different spatial perspective, depth of field and emotional feel from longer focal lengths. (I could go on a long time about this, but feel like I'm rambling enough already!) When shooting wildlife, we're generally stuck with being far away so our lens choice is made for us. When we can change our position relative to the subject, don't just zoom to the frame you want, try to think about what you want the pic to look like, and what focal length will deliver that. Then get yourself to where you need to be. A big downside, btw, of shoot wide and crop is that you're now shooting everything more or less wide angle, and for people anyway, this is often not particularly flattering. Doing so takes a major contributor to the image out of the equation.
I find irony in that I'm now about to hit 'post quick reply'