Compost is not particularly high in essential nutrients, (N-P-K), and is considered a soil conditioner rather than a fertilizer. However, organic matter is a valuable soil amendment because it: can improved soil structure, aids in necessary microbial activity in the soil, attracts beneficial insects such as earthworms, can suppress several soil born diseases and holds its nutrients in organic or slow release form, allowing for availability throughout the growing season. While there are many methods of composting and many composting bin styles, there is no best method. As the bumper sticker says, "Compost Happens". The important thing to remember is that you can never add too much compost to your soil.
You can till compost directly into the soil or add some as a side dressing to established plants.