Azaleas have shallow roots. They can survive minor droughts if they are mulched properly. They should be watered the first year they are planted. After that they should be OK except for severe droughts. Fortunately they show when they are dry.

Here is a link that might be useful: How to grow rhododendrons and azaleas.

Just be careful of the oak roots when planting. Live Oaks are very shallow rooted, as well. You wouldn't want to harm your extremely valuable trees in order to plant azaleas! ;-)