Welcome Thomas to Lawnsite,
John had a very good answer about the business side. EDUCATE yourself on business by books or programs or classes if you feel you are clueless. I would like to add one little thing. There is more than one way to skin a cat or run a business. No two people would run the same business the exact same way.
You asked about CPA's, Lawyers, etc... If you are comfortable with doing those duties for yourself you can, or you can get advise, or you can hire it done. I think most do it themselves due to startup costs or lack of those funds and eventually hire it out when it becomes more time consuming or complicated.
Usually hiring the pros for those duties saves you some aggrevations down the road for many people. But, be also aware that CPA's and Lawyers are just like Landscapers and Lawn Mowers, some are better than others. They can also screw you up if you have no idea about what is really going on and you just take their word for it. This is why I believe starting out doing those duties you can yourself, makes you less of a risk for a bad CPA or lawyer.
West Lafayette, Indiana