Use sRGB (which you should set up in your camera too - it's default), any of the other options will just produce washed out bland colours unless you know what you're doing, are printing your photos and have specialist equipment including a correctly calibrated wide gamut monitor.
'Resolution' doesn't matter, have it at 300 or 240, it doesn't affect the image, the only time it matters is when you're printing and then you can change this later.
There are some great descriptions of why to use the other color spaces on this thread.
Basically you only want sRGB if you are not doing any processing and going straight to the web, or a printer that only supports sRGB.
If your doing any editing you will want Adobe RGB or ProPhoto RGB. These are wider gamut color spaces and represent more colors than you can typically view on your monitor. So why would you want extra colors you can't view anyway? It becomes helpful when you do any adjustments. Things like fill light, highlight recovery, curves, levels. All these things will pull extra detail out of the colors, but it works best if they colors have not been clipped down to the sRGB color space.
The only downside of using these larger color spaces is you need to remember to convert back when you export. The web only understands sRGB (with minor exceptions). So if you don't convert back to sRGB on export it will look washed which is what HawkinsT is talking about. Lightroom automatically does this conversion for you on export. Photoshop will also do it if you use Save For Web.
Unless you have a clear understanding of color management, stick with sRGB, and make your "big" changes to exposure, color, contrast, etc. during conversion and watch your histogram. At the point you export, then, you have very little to worry about with out-of-gamut colors.
There are specific reasons to use other color spaces, but using them without understanding the implications can easily cause far more problems than it solves.
ok, i understand the color spaces and what they do, if i post process i want adobe RGB, that gives me the most flexibility. i guess im going to have to play with this to see how it behaves.
However, does anyone know what the "native" resolution is of my raw file? What happens if I set it at 600? 1200? I've never thought of it before, until I just happened to click on all this and said, "Hey, I have more option s I didn't know about!"
Resolution is somewhat pointless until you go to print. Even then it's mostly ignored because you often specify exact print sizes.
At 300 resolution (dpi) your native image would print at 17.2" x 11.5"
Change it to 600 and it prints at 8.6" x 5.8" with twice the detail.
But it really doesn't matter, because you just tell the printer the final dimensions when you print it and it changes the dpi on the fly to match.
In the end it's just a number that converts the size of a pixel into real world dimensions on a piece of paper. No matter what you set it to it makes no modifications to the actual image or it's pixels.
