Brandon, I totally disagree with many of the responses posted here. I've started several companies and I took on personal debt every single time. But like you're thinking, I always kept the amount within a range that I thought I could pay back if my latest entrepreneurial dream fell through.
Contrary to popular opinion, BANKS and CREDIT UNIONS do lend money to entrepreneurs. Monitor your credit score and get to know the president or vice presidents of your local independent bank or credit union. Believe it or not, they will lend money if you have a good credit score and they believe in you and your idea. They won't lend you millions, but they will lend $5k to $40k or more. Especially if you use the money to buy things - things that they can consider collateral.
When I needed to use the money to pay people or buy advertising they often helped me 'discover' collateral I didn't even know I had - like sports card or coin collections, or equity in a used car. But there have been a handful of times when I had no collateral and I was able to get signature loans. Signature loans will have a slightly higher interest rate (around 7% these days) than a collateralized loan.
And I have borrowed money using the equity in my house several times. Almost every business owner I know has done it. Just be careful not to put yourself out too far on a limb.
One other thing... offer to take the bank president or VP out to lunch. Even if you don't get the loan the guy will probably give you a fortune worth of free advice. I feel like I've received a free MBA by offering to buy lunches for people like this.