That book basically IS a tutorial, albeit a very pretty one with lots of pages and a CD. The book is designed to teach you DarkBASIC, not programming, although it starts of at a very low level (so you should find it easy).
If this is your first programming language EVAR, then it may take a bit of time to accomplish even the simplest things - This is unbelievably normal, so don't worry about it.
It's important to know things like a 'string' is basically a 'string of text', and all writing has to be enclosed like this:
"Text"
Then, you've got things like variables. If you've done algebra, then think of it kind of like that. So you could do things like:
x=3
If 'x' doesn't already exist, then it's created on the spot. Now, whenever you or a function asks for the value of 'x', it gets 3 (if you haven't changed it to something else.)
Variables, unlike algebra variables, can have more than one character making up their name:
MyVariable=4
The greatest thing about variables, is that eventually you can do things like this:
` This is a comment. Use comments
` to give your code readability for the poor people
`who don't know what you're trying to do.
`The 'print' command is a very simple way of 'printing'
`text to the screen. So:
print "Welcome to my multiplying program!"
---------------------------------------

---------------------------------------
` The 'input' command gets input from the user.
` You GET the input when they hit 'Enter' after typing.
`(My variables here are called Bob, Jim, and Jane just
` to demonstrate that you can call them ANYTHING
` (that starts with a letter.))
input "Enter the first number: ",Bob
input "Enter the second number: ",Jim
`Multiply them together!
`In programming languages, you use '*' instead of the 'x' sign.
Jane=Bob*Jim
print "The first number times the second number equals:"
print Jane
`In DarkBASIC, waits for the user to hit another key before
`continuing
wait key
`Stop the program.
end
----------------------------------
Okay, so what's the actual outcome of the program?
(The keys I pressed (when prompted) were 31 and Enter, followed by 24 and Enter. Everything else our program did

)

(Step1: Entering first number)

(Step2: Entering second number)

(Step3: Processing & getting results)
If you've got DarkBASIC, Copy and Paste the code into DarkBASIC and it'll work
IF that seems too complicated, all the code boils down to is this:
Quote: "
input "Enter first number: ",Bob
input "Enter second number: ",Jim
Jane=Bob*Jim
print "Result: "
print Jane
"
An important thing to understand is that Bob, Jim and Jane are numbers.
So, if Bob was 21 and Jim was 24, then Bob+Jim would be 45.
Now, variables can be turned into text via the '$' trailing character.
So, we could have Bob$, Jim$ and Jane$.
Because they are now strings (text), we CANNOT assign numbers to them, OR treat them like numbers.
With strings, you can do:
Bob$="Hello! "
Jim$="Text testing program"
Jane$=Bob$+Jim$
print Jane$
(Note: 'input' can do strings, too.
Input "Enter writing: ",Bob$
Jim$=" SAMPLE"
Jane$=Bob$+Jim$
print Jane$)
Damn, I've written a bloody tutorial... Again....
How's my typing? Phone 0800-GO-TO-HELL