My significant other and I purchased our home (in the state of Iowa) back in November of 2003. However, the deed, the mortgage, and all other bills relating to the house are in my name alone. He gives me cash every month to help with the bills. Recently I have considered breaking things off with him, and am curious to know his rights and my obligations to him in regards to evicting him from the premises. We have no written contract in place. In researching this I am finding a lot of mixed information, from asking him nicely to move out, to legal eviction via the court system, to charging him with trespassing if he does not leave when asked. I really want to make sure I cover my hind end to avoid any further conflict with this person. Any direction you can give me on this would be greatly appreciated!

First... ask him to leave. It's the nice thing to do.

If that doesn't work, then file the required notice (30 days in most areas) in writing... registered mail so you can prove receipt. Then if they refuse to leave at that time then file the legal eviction process just like they are renters that won't leave. That apllies to everyone related or not.

After all, it would be a lot harder if they have their names on the Mortgage or deed.

Or... Spend a few bucks, Hire a local realestate lawyer to draw every thing up for you and have the papers served. May be worth the money to avoid direct contact yourself. And they will be intimately familiar with your local laws and regulations on the topic so you don't make a mistake.