Hi Celeste. Welcome and your shots look nice. My advice on lighting is start by using one light even if you have more. Position at different spots to get a feel of effects. Then add either another light of a reflector for fill. Then add a background light or 2 even better. Now I know most folks like softboxes and umbrellas, which I use too but for an interesting look I often use my beauty dish (without the sock I might add). With dogs it can be tricky because it does give shadows and contrast but you just need to be aware and focus on fill. I also use my 580ex II with a small softbox (no gary fong diffuser for me, I have one but softbox blows it away) almost all the time on outdoor shots for fill. That will also give you great catchlights also when using primarily ambient light. Practice practice practice is key with lighting. Oh, and get a light meter. They work and save a ton of time!

Again welcome and look forward to your posts. John and Jim above, among others here, are great folks with awesome advice.