Answer: Azaleas can be planted in the spring, yes. Be sure they have been acclimated to being outside and are not fresh out of a sheltered greenhouse, and also be sure they are rated hardy for zone 6. They will do best in morning sun or bright dappled light all day. They require an acidic soil that is humusy and evenly moist yet well drained, meaning not soggy. They will not grow well in heavy clay soil.
There are many perennials that would grow well in your zone in full sun. Some easy to grow types would include Phlox subulata, daylilies (Hemerocallis, some a foot tall or so), sedum (many varieties inlcuding some very short ones), purple coneflower (Echinacea purpurea) and black eyed Susan (Rudbeckia hirta). These will all do well in average soil and are somewhat drought tolerant once established. Many of the shorter perennials such as thyme that do well in full sun also require a well drained soil or they will not survive the winters.
It is a good idea to use a layer of organic mulch several inches thick year round. It helps keep down weeds, rots down and replenishes the soil, and also helps maintain a more even soil moisture level. To know if you need to water, use your finger and dig down into the soil below the mulch. If it is still damp you do not need to water yet. When you do water, water slowly and deeply so it sinks in. After watering wait a few hours and then dig down and see how far it reached; sometimes this can be surprising.
If you are planting perennials you will need to loosen and amend your soil with organic matter such as compost or well rotted leaves to help improve its structure and provide a good deep rooting environment. This will also help reduce watering needs in the long run. I would suggest you consult with your county extension to test your soil to see what other amendments might be recommended.
Your local county extension and garden center staff should be able to help you analyze the growing conditions in your yard and suggest plants that would do well there for you with minimal work. I hope this helps you get started in your planning.
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