RAilings
36" minimum height when surface is 30"+ above grade
200 lb concentrated load
50 lb concentrated load over 1 sqft of balusters
50 lbf vertical and horizontal load along top rail
4" maximum gap between deck and underside of bottom rail
4" maximum gap between balusters
34" minimum stair rail height from nosing to top of rail

Thirty-six inches is the most common residential height, but some jurisdictions vary.
Joist connected posts: many possible ways of securing posts into the framing.
Baluster calculations
Stairs
Minimum 36” at all points above the permitted handrail height
Minimum 31.5" width below handrail height where handrail on one side
Minimum 27" width below handrail where handrails on both sides
Maximum rise of 7-3/4” - maximum difference among risers 3/8"
Minimum tread width of 10" - maximum difference among treads 3/8"
Connecting stairs to deck: Extended backer board below rim joist. 
Attachment methods vary depending on the style of stairs 
but this is very common and reliable technique.

Stringers
Maximum 16'-6" span for solid stringer (southern pine)
Maximum 7'-0" span for notched stringer (southern pine)
Minimum 5" throat recommended
Laying out stringers:Learn the math and how to trace out the number 
and size of rises and runs to cut out your stair stringer. elevation change

Treads & HandRails - Deck Building Code Points
Maximum 36" o.c. solid stringer spacing for 2" thick treads
Maximum 18" o.c. notched stringer spacing for 2" or 5/4" thick treads
Maximum nosing of 0.75" to 1.25" - maximum nosing radius of 9/16"
Open risers: maximum opening of 4"
Closed risers: minimal nominal 1" thick riser material
Handrails must not project inwards more than 4.5" on either side of stairway

Underside of footing must be below frost line for ledger connected decks or minimum 12" below grade where no frost applies.
Floating Deck Exception: Decks not connected to ledger need not have footings extending below frost line.

Steven Foot Rule: How deep to go for footings on slopes?

 
Alternate Foundations: Free standing deck options

Tips
Through bolts, lag screws or expansion anchors should be minimum 1/2" diameter
Lag screws must go through band board at least 1/2"
Lags must be hot zinc coated or stainless
Locate upper bolts at least 2" below the top edge of ledger

Locate upper and lower bolts maximum 5.5"/6.5"/7.5" apart vertically for 2x8/10/12 respectively
Ledger board width must be => deck joist width but =< rim joist width.
Minimum size is 2x8
Corrosion resistant flashing is required for connecting to wood framed buildings

Covenants and easements

There is no building code for decks,Instead, a single code for residential building.  

Drop into local city building department and chat officials RE any covenants specify size,style,location,material restrictions.

An easement is city bylaw-regulation related to use and access of a property.  
It allows your neighbors or public officials access to a portion of your property.

Make sure you don’t build in a way that impedes this access. 
If you own your property you should have an entire history of its title from when you purchased the property.

setbacks and variances

You can't build in a setback area. The city will tell you right up front what the setbacks from property lines or sidewalks are.
There are usually limits to how close your deck can be to another building. 
A variance is a rarity. Basically any regulation can be challenged and depending on your circumstances, may be set aside or "varied".