How to share a SharePoint site (2013)
You want to share a site with another individual within our organization
Step 1. Click 'Share' in the top right corner
Step 2. In the first box you can enter Name, Email Address, EID, or Everyone
Step 3. Add a message to recipient
Step 4. Click 'Show options'
Step 5. Choose to send an email invitation to the recipients
Step 6. Select a group to add the user(s) - defaults will include 'Full Control', 'Edit', and 'Read' permissions