Here's a quick review of the hard lessons I have learned. Trust me you don't want to learn the hard way:
1. I know this has been said but don't try to get business by underbidding. It seems like you will make more money but think about it this way:
Mowing for even $5 less means a lot more to you than it does for the customer because if you mow 20 lawns per week for $5 less than you could have charged, that's about a $400 difference for you, but only $20 for the customer, at the end of the month. And if the customer cares more about saving a little money than getting good service, it won't be long before he replaces you.
2. Don't underestimate the challenge of this business. I learned the hard way that you can quickly lose those customers you worked so hard to get, so don't slack off.
Those two lessons have been long hard lessons for me, so I leave them here for the new guy to think about.
LawnBoy push mower
Echo SRM 225
Hitachi Handheld blower
'99 Ford Ranger XLT