DeeDee,
first the meter: I guess if you're shooting available light, getting an incident reading (where you hold the meter at the subject and read the light hitting it) would be helpful. But that begs the question of why you're shooting available light indoors if you don't have to.

If you're using flash, why not just take some test shots and look at the results on the camera. Use the histogram if you can't tell from the actual images.

As for ACR and PhotoShop: there are a lot of very good RAW conversion programs out there -- PhaseOne, Bibble, Lightroom, Aperture -- but I stick within the PhotoShop program for simplicity and consistency. Once I set up in a location, I take a photo of a white towel and that's the first image I make adjustments to. Then, when I get the towel image to turn out white, I save the settings in ACR as something like "PerryPoodles" and that's my setting for every other shot under those lighting conditions.

What I like about shooting RAW is that I can adjust color balance, contrast and skin tones and apply sharpening later with plugins that do a better job than the camera does with its jpeg algorithms.

As for backdrops, it's fairly easy to find raw muslin at any JoAnn's and then to dye it the color(s) you prefer. But, if you don't like the crinkles, you might want to consider canvas. As a painter, you'd like this. The only downside is that canvas is very heavy to tote around and you need to put it on a frame to keep it stretched.

I've found that the key to portraits -- whether it be of people or pets -- is to control the lighting. Even if you're doing available light (not recommended), try to stay in one location so the light doesn't change. That way you can have consistency in the images.

Cheers,

Jim