Navigate to the General tab within your Settings and tap the Restrictions option on the right hand side. You will notice that Restrictions is turned to Off by default. To enable Restrictions, simply tap the Restrictions tab to choose what is accessible and not accessible for the user.
Once you choose to Enable Restrictions, you will be asked to create a 4-digit passcode specifically for this purpose. This code should probably be something different that you use to unlock your actual device. The recommendation would be to choose a passcode that cannot be easily figured out by users that you are enabling restrictions for and will not be forgotten by the parent/guardian.
Once you have decided on a passcode for your restrictions, you can now begin disabling specific apps and the age-appropriate content that you want accessible by your student/child. Keep in mind that these restrictions can be changed at any time as long as you remember your restrictions passcode.
One of the more powerful options when thinking about what Internet content you want your student/child to have access to is the option under Websites. When selecting the Specific Websites Only option, you will be able to select which sites are available for the user to access.
If you ever want to add a website to the list of accessible sites, just select the Add a Website option and enter in the website name and URL address and it will then be added to the list of allowed websites.