Hi all, I'm a bit of a photography novice so am looking for some advice. I have just ordered a Speedlite 600EX-RT (and was persuaded to get an ST-E3-RT at the same time!). The reason for this was that I was having trouble getting non-blurry photos at a recent family gathering. It tuned out I had accidentally switched the ISO from Auto to 100, but by the time I discovered this I had paid for the flash! There have been a few occasions when I genuinely needed a flash so I'm not too worried.
From the above, it is clear I don't really know what I am doing. Can anybody point me to a "flashes for dummies" primer so I can take advantage of my new kit? I do landscapes (which are unlikely to need a flash), portraits and wildlife mostly (all amateur). I recently bought the 100mm macro (2.8L), which is probably where the flash will be of most use. I'm guessing the secret here is to have the flash off camera, which is why I didn't protest too much about getting the ST-E3.
I'm using a 5D mkIII and also have the 24-70 mkII and 70-200 (f4L).