Assigning tasks
You can change your default filters in the task view to look for tasks that are owned by someone other than yourself. You can also then enable the "Owner" column so you can see who owns which tasks. Please reference the GIF that demonstrates filtering by owners, adding owner column, and sorting by owners.
You can also create user groups and set task owners to that group instead of just a single person. Setting the owner is the same as you would do with a single user, but instead just assign the owner to a group. This is also demonstrated in the GIF below.
User groups can be created in the Settings-->Groups tab.