Below are instructions for sharing a folder in OS X. It is recommended to share a folder, rather than an entire drive so as to avoid connection problems. Note: The first set of steps walk you through creating a separate user account. This part is optional, as you can use your existing account(s), but it is recommended
Click the Apple in the top left and go to System Preferences
Alternatively you can click the System Preferences icon in the Dock
Now click Users & Groups
Click the Lock in the bottom left
Enter your Password for your account and click Unlock
Now click the "+" symbol
Set New Account to Standard (you can choose Admin if you like)
Enter a Full Name (the Account Name will auto-fill)
Enter a Password for this account
Note: It is recommended to use a different password than your primary account
Enter a Password Hint if desired and click Create User
If the Automatic Login prompt appears click Keep Automatic Login
Click Show All
Under System Preferences click Sharing
Check File Sharing and click Options
Make sure Share Files and Folders using SMB and Share Files and Folders using AFPare checked
Put a check next to your newly created Shared User and click Done
Now enter the Password for the Shared User account
Click Ok
Click Done
Now drag the shared folder(s) into the Shared Folders window
Click on the shared folder and click the "+"
Highlight the shared user and click Select
Connecting the remote computer(s) via IP works best
You will see the IP listed above the Options button
Alternatively you can follow these steps to find the IP of your computer