Here is a checklist type guide and help on some of the more difficult part of Earthbound as well as some handy-dandy hints and tips (that almost everyone already knows).
1) Go talk to Pokey on the Mountain
2) Return home, sleep, then answer door.
3) Find Picky and Buzz Buzz at top of Mountain
4) Take Picky back to his house and lose Buzz Buzz. Go home.
5) Go to town and get Mr. Baseball cap from clubhouse.
6) Get assorted needed items: map (library) yo-yo and bracelet
7) Defeat Frank and Frankystein Mark II.
8) Talk to Mayor B.H. Pirkle and get the Key to the Entertainer's shack.
9) Defeat Titanic Ant and Claim the 1st "My Sanctuary".
10) Get taken by Cptn. Strong to Station.
11) Defeat police and gain access to Twoson.
1) Get Bicycle from shop
2) Get items from Store. (slingshot)
3) Go to Burglin Park and Defeat Everdread.
4) Go to Polstar Preschool and talk to everyone.
5) Give $200 to the Apple Kid.
6) Get reciever phone from mouse.
7) Walk up to iron pencil statue.
8) Return to town and recieve call from apple kid.
9) Meet him at Burglin Park and recieve pencil eraser.
10) Return and use eraser on the pencil. Poof, it's gone.
Happy Happy Village:
1) Continue through Peaceful Rest Valley to Happy Happy Village.
2) Get items at store (Bat, Holmes hat)
3) Head through cave to North of Village to a shack.
4) Get Franklin Badge from Paula in the shack.
5) Go through Cultist's main building and defeat Carpainter.
6) Get key and free Paula.
7) Level her up a bunch.
8) Claim my sanctuary location in cave to west in Happy Happy Village.
9) Return to Twoson and take Paula to her home then to Everdred.
10) Get wad of bills from Everdred.
11) Show guy at Chaos Theatre the money to free the Runaway five.
12) Watch the show. Get a ride from them to Threed.
1) Go to the Zombies north of the town. Try to talk to them.
2) Go to the hotel and follow the Lady inside and get attacked by the zombies.
3) Paula will contact Jeff.
1) Wake up.
2) Talk to The guy down stairs to get the bent key.
3) Try to open lockers.
4) Return and trade bent key for Bad Key Machine.
5) Open lockers and get equipment.
6) Leave the School and go to shop.
7) Buy some gum from the girl and give it to the monkey near the door. He will follow you.
8) Head south to the Tessie Watching club and sleep in the tent.
9) In the morning walk to the tip of the land and give some gum to the Bubble Monkey.
10) Get on Tessie and go to other shore.
11) Proceed through the cave and talk to Brick Road.
12) Go to the Lab just past Stone Henge and talk to Dr. Andonuts.
13) Enter the Sky Runner to go to Threed.
Threed and Saturn Valley:
1) Use Bad Key Machine on the locked door.
2) Defeat the Tent at the bottom of the town to get the Fly Honey.
3) Get the call from the Apple Kid.
4) Use Zombie Paper in the Main Circus Tent.
5) Sleep at the Hotel and go to the ladder at the top of the map.
6) Go through the cave and valley to get to Saturn Valley.
7) Marvel at how incredibly cute the Mr. Saturns and their assorted related objects are.