For recomended adventures:
-the keep in the borderlands: a clasic, gives you a starting base for the players and has enemies that you can talk, reason, ally and betray... but also just kill if you want.
- Sinister Stone of Sakkara: beacuase is the starting adventure created fot this game.
- Dyson´s dodecahedron (https://rpgcharacters.wordpress.com/) has many maps for free and some adventures (some free others not)... I personaly love the maps as they are complex and originals without loosing a clasic dungeon feel. you can the fill the maps using the rules in acks for filling dungeons and come up with cool stories to personalize the dungeons.
- one page dungeons: will save your soul by giving you a LOT of small dungeons to populate your world. also it has some cool big dungeons. My favorite was "seven spindles and a mcguffin" (it takes some work to stock with monsters as you need to create your own random encounters tables, but the map is great and the 7 rotating hallways are a lot of fun)
- one good way to start the adventure and give the feel of open world is having more than one dungeon ready and give them to chose based on rumors of diferent places to go. (generaly i give 3 options: one big dungeon and two smaller ones)
-This will save lots of times rolling random encounters, stoking dungeons, and rolling for treasure: http://aryxymaraki.pbworks.com/w/page/77366768/ACKS%20Toolkit
-this is wath i use to make maps: http://www.hexographer.com/
-this is the spreadsheet that i use to keep track of xp and treasure, you juts have to create a column for each player and hench, put how much of a share they have, and how much is their xp bonus in the form of and equation. https://docs.google.com/spreadsheets/d/11AKEtRmLCmJTwwFNIh63p9H4I1w1cn7a1uWQ9pYGpxo/edit?usp=sharing
its not perfect, and you may like to create your own... but seriusly dont do it by hand, this is more work up front, but loots of less work later.
- this is the spreadsheet that i use to keep all domain related info, it includes a space for individual domains (likes the pc´s), a quick view for unmanaged domains (that includes an equation to calculate pop, bigest city, and number of leveled character given X size of a kingdom) and a tool for calculating trade modifiers based on trade routs. https://docs.google.com/spreadsheets/d/1QhCYdJdq3q5omdpTeHSZIR59tzHEZRjqOc7MemwQ0_A/edit?usp=sharing
again, not perfect and some in spanish.
-for house rules:
its good that you give maximum HP for first level.
make a selection of what clases you want in your game (they are all good, but maybe not all fit your setting).
consider giving the thief the posibility to trade pickpocket for another class proficiency. (this will result in the thief being unable to use the steal hickjicking later, but it may be really usefull at the beggining) or just give one more proficiency to the thief, they could really use them.
Improving atributes in game: Each time your character gains a level, choose an ability and roll 3d6. If the result is greater than that ability's score, it increases by 1 point. it gives you a moment of fun and tension aditionaly to rolling the hit dice, and helps more the pour soul with low atributes than the monster with all 14´s.
this is a chart to determine the value of the land based on the characteritics of the land instead of a purely random dice roll: https://docs.google.com/spreadsheets/d/1losJftMYk5VnOaWk6W9Y2q56D4ovVdk00tpHYwwlavA/pub?output=html
and you may also want to implement this rule to balance the gold gaining power of thief late game: http://www.autarch.co/forums/general-forums/general-discussion/limiting-hijinks-type-settlement
this is a really usefull link to the prices of magic items: http://www.autarch.co/comment/10345#comment-10345