What you seek to do can become a rewarding undertaking. Limited knowledge of a particular field, such as nursery operations, usually indicates that the first order of business is to gain knowledge. Every state of the union has a land grant college and a vast library of information specific to nursery management techniques for that particular state. You can take advantage of that information if you live near the land grant college. Rutgers University is the land grant college for New Jersey, Penn State for Penna. Cornell for N.Y. If you do not live near the college, I am pretty sure you can access a vast wealth of knowledge through its library affiliation program and access on inter-net. An associated resource is the co-operative extension service of the state land grant college. These professionals and their resources are supported by tax dollars. Their services are one of the greatest values and assets provided to the citizens by their government. Take advantage of them. Believe me, I have met only the nicest and most helpful people in the co-operative extension service.
I recommend that you start by inviting the county agricultural extension agent (Horticulture specialist, if available) over to your place for a walk-around and a chat. You can also take advantage of the services of the soil conservation specialist or the forestry specialist. If you are looking to first build the soil, on which your nursery crop will depend, you might first talk with the agronomist about improving your soil through cover crops. If the land is sloped, talk to the soil conservationist about contouring and terracing.
Most of all, determine some of the basics of the industry as applicable to the crop you plan to grow. Keep in mind that whatever it is that you choose to grow, you will have to culture it in a manner that makes it marketable, you need to get it out of the ground (such as balled and burlapped) and into the hands of your consumer in a timely fashion. Folks do not want Christmas trees in July nor ????? willows in June.
I might suggest that you keep it real simple in the beginning, I mean r e a l simple. Start with small flowering deciduous shrubs which are less expansive to line-out (nursery talk for "Planting in the field"), easier to culture and dig. Learn about your land, what it needs and what insects, diseases and varmints you have to control. Subscribe to trade magazines such as "American Nurseryman" and get hold of some local wholesale growers' catalogs to see what they are growing and prices fetched. Go on-line and look up the names of the plants you are considering. While reading the articles about those plants, take notes about their requirements and write down key pests. Run Internet look-ups on the pests and you'll find an inexhaustible source of information published by the various land grant colleges and private concerns which can be a great resource for you. Spend a few bucks and get some text books on the fundamentals of Horticulture and Nursery operations. There are many excellent booksellers who specialize in books for this industry. Please understand that if you think you are going to stick some acorns in the ground and come back a few years later to find a salable oak tree, you will be sadly mistaken. For most smaller operators, the dedication to a well run nursery is all encompassing and a fully involved way of life, similar to the demands of dairy farming or any other serious farm venture. A nursery is a farm of high value crops and therefor, the risks can be high. Dedication and perseverance can be very rewarding in this field and it can be done successfully "on the side" if planned and executed carefully.
Most undertakings look simple until you attempt to execute them. Is is then that the execution and undertaking might end up being practiced on you.
I did not say it earlier, but start your journey with some soil sampling. Use the test kits which are available from the county agents. You cannot know what kinds of cake you can bake until you know what ingredients are in the pantry. The soil is your pantry and its contents oftentimes require some adjusting in order to meet the requirements of the plants you desire to produce.
Best of luck to you.