I'm trying to learn Haskell, but the small bit of sample code I tried to write is running into a fairly large amount of "Couldn't match expected type" errors. Can anyone give me some guidance as to what I'm doing wrong/how I should go about this?

These are the errors, but I'm not really sure how I should be writing my code.

toDoSchedulerSimple.hs:6:14:
    Couldn't match expected type `[t0]' with actual type `IO String'
    In the return type of a call of `readFile'
    In a stmt of a 'do' block: f <- readFile inFile
    In the expression:
      do { f <- readFile inFile;
           lines f }

toDoSchedulerSimple.hs:27:9:
    Couldn't match expected type `[a0]' with actual type `IO ()'
    In the return type of a call of `putStr'
    In a stmt of a 'do' block: putStr "Enter task name: "
    In the expression:
      do { putStr "Enter task name: ";
           task <- getLine;
           return inFileArray : task }

toDoSchedulerSimple.hs:34:9:
    Couldn't match expected type `IO ()' with actual type `[a0]'
    In a stmt of a 'do' block:
      putStrLn "Your task is: " ++ (inFileArray !! i)
    In the expression:
      do { i <- randomRIO (0, (length inFileArray - 1));
           putStrLn "Your task is: " ++ (inFileArray !! i) }
    In an equation for `getTask':
        getTask inFileArray
          = do { i <- randomRIO (0, (length inFileArray - 1));
                 putStrLn "Your task is: " ++ (inFileArray !! i) }

toDoSchedulerSimple.hs:41:9:
    Couldn't match expected type `[a0]' with actual type `IO ()'
    In the return type of a call of `putStr'
    In a stmt of a 'do' block:
      putStr "Enter the task you would like to end: "
    In the expression:
      do { putStr "Enter the task you would like to end: ";
           task <- getLine;
           filter (endTaskCheck task) inFileArray }

toDoSchedulerSimple.hs:60:53:
    Couldn't match expected type `IO ()'
                with actual type `[String] -> IO ()'
    In a stmt of a 'do' block: schedulerSimpleMain
    In the expression:
      do { (getTask inFileArray);
           schedulerSimpleMain }
    In a case alternative:
        "get-task"
          -> do { (getTask inFileArray);
                  schedulerSimpleMain }

This is the code itself. I think it's fairly straightforward, but the idea is to run a loop, take input, and perform actions based off of it by calling other functions.

import System.Random (randomRIO)
import Data.List (lines)

initializeFile :: [char] -> [String]
initializeFile inFile = 
    do  f <- readFile inFile
        let parsedFile = lines f
        return parsedFile

displayHelp :: IO()
displayHelp =
    do  putStrLn "Welcome to To Do Scheduler Simple, written in Haskell."
        putStrLn "Here are some commands you might find useful:"
        putStrLn "    'help' : Display this menu."
        putStrLn "    'quit' : Exit the program."
        putStrLn "    'new-task' : Create a new task."
        putStrLn "    'get-task' : Randomly select a task."
        putStrLn "    'end-task' : Mark a task as finished."
        putStrLn "    'view-tasks' : View all of your tasks."

quit :: IO()
quit = 
    do  putStrLn "We're very sad to see you go...:("
        putStrLn "Come back soon!"

createTask :: [String] -> [String]
createTask inFileArray = 
    do  putStr "Enter task name: "
        task <- getLine
        return inFileArray:task

getTask :: [String] -> IO()
getTask inFileArray = 
    do  i <- randomRIO (0, (length inFileArray - 1))
        putStrLn "Your task is: " ++ (inFileArray !! i)

endTaskCheck :: String -> String -> Bool
endTaskCheck str1 str2 = str1 /= str2

endTask :: [String] -> [String]
endTask inFileArray =
    do  putStr "Enter the task you would like to end: "
        task <- getLine
        return filter (endTaskCheck task) inFileArray

viewTasks :: [String] -> IO()
viewTasks inFileArray =
    case inFileArray of
        [] -> do putStrLn "\nEnd of tasks."
        _ -> do putStrLn (head inFileArray)
                viewTasks (tail inFileArray)

schedulerSimpleMain :: [String] -> IO()
schedulerSimpleMain inFileArray =
    do  putStr "SchedulerSimple> "
        input <- getLine
        case input of
            "help" -> displayHelp
            "quit" -> quit
            "new-task" -> schedulerSimpleMain (createTask inFileArray)
            "get-task" -> do (getTask inFileArray); schedulerSimpleMain
            "end-task" -> schedulerSimpleMain (endTask inFileArray)
            "view-tasks" -> do (viewTasks inFileArray); schedulerSimpleMain
            _ -> do putStrLn "Invalid input."; schedulerSimpleMain

main :: IO()
main = 
    do  putStr "What is the name of the schedule? "
        sName <- getLine
        schedulerSimpleMain (initializeFile sName)

Thanks, and apologies if this isn't the correct place to be asking such a question.