If that's the way you are choosing to start your business, thats up to you. I just hope you as honest with your customers, and that they know the person using equipment on their property is uninsured. I would at least talk to a couple agents and get quotes you may find that insurance is cheaper than you thought. I know when I first switched my truck to commercial registration and insurance I saved about $1,400-1,600 a year. But that all depends on vehicle, driving record, where you live, ect. I think I was quoted around $500 a yr for a 250k/500k general liability policy.
As far as pricing, yes that comes from experience. Get a measuring wheel to start with and do the math out, a yard of mulch will cover about 100 sq feet at about 3" deep. Eventually you will be able to eye ball an area and get an estimate for mulch needed and time for weeding, edging, spreading, etc... As far as time goes, you should be figuring the time it takes to estimate the job, gather materials, drive to and from the site, all into the job time and bill accordingly. The fuel you use for these trips should be figured as a material to.
The reason I don't agree with giving a separate price for labor and materials is that the customer with often try to compare those to another company. But often they are not comparing apples to apples. Often with a newer company charging for materials many customers will not understand why you are charging xx.xx per yard when they can get it delivered for less themselves. Abigail piece of advice I'll give you on this is to sell your product, inform the customer why your mulch is better, and inform why you are a better choice, do you spend more time weeding, cleaning etc? are you cheaper? Being cheaper will work in the short term but may limit how far you can take the company.
Why do people not respect us as they do other tradesmen? Because every Tom, Dick, and Harry doesn't think he can be a plumber or electrician!