I'm fairly new to blender, just getting started with basic modelling, and working my way through the huge noob to pro tutorial on wikibooks.

I've run into a few things which are confusing me, though.

1. When making some things, especially landscapes, I tend to go a bit overboard with fractals and subsurf, and end up with hundreds of thousands of vertexes, and a lot of unnecessary detail. Is there any easy way to lower the level of detail of a model. Say automatically uniformly deleting vertexes to reduce complexity with a minimal loss to detail?

2. Textures only seem to show when rendering. I find this a bit annoying. Is there any way to make the models show with textures in realtime while editing? Obviously not with full shadows and lighting, but I'm sure just drawing on the texture is reasonable to do on the fly, no?

3. Actually, textures are confusing me in general. Some of the tutorials on landscape modeling used textures as heightmaps, and although I made it work, it felt like following mysterious, arcane steps. And I still don't understand how or why it works. Can anyone direct me to an indepth tutorial on applying textures?

Also, unrelated, but This is the first thing I've made without a tutorial to show me how.

I kind of bumbled through applying the color to it, and I still don't understand how I did it, beyond hitting random buttons in the textures and materials panels.