How do you groom a short-haired dog?

I know that medium to long haired pups typically go to the groomer to be washed and blown out and to have their nails trimmed and that other “business” done to their behinds…but what about my short haired dog?

She is a chihuahua.

How often should I bathe her or trim her nails? And does she need that other “business” done?

I haven’t experienced any problems or anything, just want to make sure I am doing the right things for her. I am a first time dog owner. = )