Stair Cases and Landings:
A well thought out and designed staircase can really be the signature on your new deck project. Most municipalities require that the steps be at least 36” wide. However I would recommend the steps be at least 48” wide at a minimum. When you are planning a stair case you also want to consider the pedestrian traffic. Try to locate them in close proximity to your exterior door on the house. The reason is to keep your traffic flow from having to walk around your patio furniture and other obstacles to enter your home. The last thing you want to do is to turn your deck into an obstacle course.
Extra wide steps, or flared and wrap around stair cases have become increasingly popular in today’s deck designs. They add a whole new look to the design of the deck and also offer two way traffic flow for convenience and entertaining. You want a staircase to be inviting and to say welcome when your guests arrive. These types of stair cases work the best when the elevation of the deck is 48” or less.
On deck projects were you have a high elevation and 10 or more steps you might want to consider adding a landing. Generally a landing is added at the mid point of the stair case and either continues straight on to grade or exits left or right off of the landing. 
In some cases you might want to consider making the landing large enough toreturn the steps back in the opposite direction sort of like making a U turn.Most stair cases are constructed using 2x12 pressure treated stringers, and are generally spaced from 12” to 16” on center base on the materialsyou are going to use. Also keep in mind that you can leave the risers open for ease of cleaning but I like to recommend closed risers for safety reasons.
Some deck designs require spiral stair cases because of property limitations or set back requirements from your counties zoning regulations. Most spiral stair cases are made from aluminum or steel and can get quite expensive. Spiral stair cases look great but when it comes to functionality you are limited because of the difficulty in getting furniture or other large objects up or down them.