The General'a Handbook has been released for Warhammer: Age of Sigmar and there are a lot of questions on Matched Play at the moment. With this post I aim to clear up the processes of writing your army list and rules changes. Everything here is extrapolated from the General's Handbook.
Agree on any house rules.
• Campaign System
• Base to base measuring.
• Army selection.
Decide game type with opponent.
• Vanguard 1000 points
• Battlehost 2000 points
• Warhost 2500 points
• Points-only Game
Pick units for your army up to the game type limit, all must belong to the same Grand Alliance.
• Select Warscroll Battalions as desired.
• Meet minimum Battleline and leader requirements.
• Do not exceed Behemoth and Artillery limits.
• Pay for multiples of the minimum size unit, below strength units are rounded up.
• Decide reinforcement points and note any leftover points.
Determine Army Allegiance. You may choose a Grand Alliance Allegiance even if you have selected your army under a Faction Allegiance to unlock Battleline units.
• Choose Army General.
• Note Battle Trait.
• Select Command Trait.
• Select one Artefact (additional one per Warscroll Battalion) and assign max of one to each hero.
• Note all details on army roster.
The Player with the most leftover points rolls for a Triumph.
Roll for Matched Play Battleplan.
Use reinforcement points to add new units to the game.
• Any new unit which is to be added must be paid for with reinforcement points.
• If the spell or ability has a random number of models you roll to determine the maximum amount you can deploy before you spend the points.
• You may deploy less than the amount rolled if desired or if you do not have enough reinforcement points.
• Reinforcement Points costs are rounded up for units smaller than the minimum unit size.
Models added to existing units during the game via abilities or spell do not use reinforcement points however the unit cannot go above its original starting size.
Monsters do not get the save modifier from cover.
Three rules of one.
• Each spell can only be attempted once per turn.
• Rolls of one to hit/wound/save always fail.
• Abilities generating extra attacks only do so once.