Greetings, GPwalker, and welcome. You asked:

<<I will be starting a Self-Directed Roth IRA very soon and I'm wondering what expenes might I occur. I would like to make monthly deductions from my checking account, but I'm questioning the expenes/fees from doing it contributing monthly or annually. Which is better?>>

As far as expenses connected with a monthly deposit, the vast majority of custodians/brokers don't charge anything for that service. Some, though, will allow only minimum deposits such as $50 to $100. For that, you'll have to check with your broker. You don't talk about how much and what you will do with those deposits. If the amount is small, then certainly you won't use them for trading immediately because transaction costs would eat you alive. In that case, the money would stay in the account as part of the broker's sweep account earning money market fund returns. If those returns are less than you could get elsewhere, then perhaps an annual deposit versus a monthly one would be better for your purposes.

Regards..Pixy