In my neck of the woods, landscape labor (unskilled) is billed out at $35-45 per man hour. Landscape design services at $50-$90 per hour. If you run your income thru a legitimate business you pay about a third of your income in taxes, etc. You've probably spoiled them by "volunteering" for so many years so they may have a hard time adjusting to paying you. You might want to call around to some reputable landscape companies and generally ask their rates for the types of things you'll be doing so you'll have some ammunition to defend your fees. Good Luck!