Actually, source control GUIs are excellent for less-technical team members. I've had great results using TortoiseSVN or the GitHub client with multiple distributed teams.

It's great to be able to tell a new team member: "Press this button to get everyone else's updates." "Press this button to push your updates to the server/current branch." Later, depending on their role and level of skill, we can cover branching, merging, tagging and other move advanced features.