First Photo Shoot - Group plus dog outdoors

[mjjgm]

I am about to go on my first portrait shoot which will consist of 3 women and one dog (Dachshund). As per their request, the pictures will be taken outside, mid-morning. So far, I've mainly been reading advice online & found the 'Outdoor Portrait' videos from prophotolife.com quite helpful.

Just looking for some additional advice anyone has to offer to help prepare me for this! If I'm missing some essential gear, I might be able to rent it so I'm open to those suggestions also. ( As long as it's within a quick learning curve to be able to use - ie not ready for strobes, etc. )

My main concerns/questions are the following:

1. Are there any good websites that have examples of small group portrait poses particularly with dogs?

2. The 3 people are all about the same height. Advice on how to deal with that?

3. Since the dog is dark-colored, should I do anything special to exposure correctly?

4. Advice on use of the speedlite? (I just ordered it & it hasn't even arrived in the mail yet so I have no experience with this one yet, only relying on things I've read like bouncing it off of a reflector.)

5. I was thinking I'd mainly use my 50mm prime lens and go for around f/8. Or would I be better off using my long lens at 75-100mm? Am I okay without a filter? If not, which kind should I get?

6. Ways to interact... Do I count 1, 2 before the shot? How to induce natural smiles? Jokes? (I'm an introvert so this will be difficult.)

7. Weather forecast is scattered thunderstorms... not too excited about that one...

Some gear I own consists of: Digital Rebel XT (+extra battery), 18-55mm kit lens w/ Haze filter (no IS, no hood), 50mm f/1.8 II lens w/ hood, 75-300mm f/4-5.6 lens (don't have a hood), a couple reflectors (42') w/ one stand & arm, tripod, speedlite 580ex II with diffuser

Thanks in advance for any advice!