Standard Redirect
This will redirect all mobile users to the homepage of your mobile site regardless of what page they end up on the mobile homepage. You can find the code for this redirect type under "Site Settings > Auto Redirect Code"
Per page redirect
This is the recommended option for redirecting users. With this redirect type you can build a map of the pages you want to redirect your visitors to. As an example if someone was to email me a link to http://mywebsite.com/our-products.aspx and I accessed it on my smartphone, the per page redirect would take me to the respective page on the mobile website (http://m.mywebsite.com/our-products.html).
As mentioned earlier you will have to build a redirect map for this to function properly. You can build a map by logging into the builder and hovering over "Site Settings" and then clicking "Per Page Redirect". You can get the code to add on your desktop website by clicking "Get Code".
The code for both redirect types will need to be added in the <head> section of your desktop website.