For US users Coinbase is one of the easiest ways to buy bitcoins. Link your bank account like you would with paypal and it's straightforward from there on.
My PayPal strategy, which I'd reuse for Coinbase et al, is to just create a separate checking account for that with a few clicks. I think the most they can screw me over is one or two overdraft fees before I tell my bank to stop ACH transactions.