Well, hopefully you know your dog and what it takes to calm her.
Gracie hates the bath but does not fight it. I just tell her what a good girl she is and how nice she is going to look and smell. I just use a normal calm tone of voice and talk to her like I usually do. I use the kitchen sink. I don't fill it with water. I can tell you about something that has made the process much quicker and easier.
Rinse Ace 3-Way Pet Faucet Sprayer at PETCO
It has three spray speeds and I love it. It has cut the bathing time in half. It does require attaching the enclosed aerator to your faucet but I'm used to doing small plumbing jobs and it is very easy to do. I also put a cover over the sink and drain so she is steady on her feet. It helps them not to panic. You can use a towel or one of these:
Rinse Ace Pet Sink Bathing Mat at PETCO
Doing it at least once a week is a good idea because it will speed up her ability to learn to cope with the process. Once she finally accepts the fact that it's going to happen despite her objections she will surrender to it. Persistence will win her over. Just don't let her think you are feeling sorry for her. Encourage her but don't pity her.
Chris Christensen has a really nice spray on cleaner called "Show Off" but right now you want to keep bathing her on a regular basis.