How to change account info and hook up iCloud to my mac?

My dad bought a laptop (macbook model A1342) a few years ago and now it's mine. However, the account is still under his name and all my files and bookmarks are on this account. Is there any way for me to change it so that it's under my name and email address?

Also the Mail application has his MobileMe and RSS accounts. I was able to login to my own account on it but is there a way to get rid of his accounts?

I have an iPhone that used to be his too, but now I have my own Apple ID and it's under my account. I'd like to hook up iCloud to get stuff from my phone to my mac, such as the Find My iPhone app, but I can't find iCloud on my computer.

Woah, woah, woah! Limit is one question. Solve one issue and it will pave the way for all the others.

Learn this about computer questions. ALWAYS tell these two things, just in case they matter:
-- Type of computer (model, processor type, processor speed-- get it from Apple logo > About This Mac).
-- Version of OS. That will be in numbers exactly, not just the big cat name.

My answer is for OS 10.6.8. Do this…
Method 1: If you have your dad's password, create a new account like this…
-- Open System Preferences > Accounts.
-- Click the padlock icon and type the password.
-- Click the + sign to create an account.
-- Make it "Administrator", not "Standard".
-- Type your choice of password, and remember it.
-- Quit System Preferences, and if it asks about auto-login, agree to turn it off.
-- Log out or restart.
-- Log in.

Method 2:
[All typing commands that follow require strict adherence to the exact spelling. This includes noticing where there's a space between characters and where there's no space.]

Boot to single-user mode (hold ⌘ and the S key for 45 seconds at startup).
Type:
/sbin/mount -uw /
Press Return.

{Nothing appears to happen, no problem.}

Type:
cd /users
Press Return.

Type:
ls
Press Return.

{You see the user account folder names -- "Shared" plus any that were created. Write down any that were created.}

Type:
rm /var/db/.applesetupdone
Press Return.

Type:
reboot
Press Return.

{Now stuff appears to happen.}

Setup Assistant appears. Create a new account, but be sure to choose a different short name than that of the original [[short name is the name of the user account folder that you wrote down]]. Then open System Preferences > Accounts, and delete his old account-- or leave it and ignore it.