Good question. As we tell our clients, you can certainly do anything on your own or use those websites, but the DIY method doesn't always work. Those sites in particular give you a "one size fits all" approach and they often miss issues (i.e. laws) that may be particularly relevant to the unique circumstances of your business. Not to be biased, since I am an attorney, but I would at least have an initial consult with one to make sure you are on the right track as far as formation documents, such as the operating agreement or bylaws.
As for the accountant side, we request that all clients meet with an accountant because taxes are not something you want to dabble in. When you start your own business, your likelihood of being audited skyrockets. That's not to say there are not plenty of business running by doing everything their own, but if you think of consulting with an attorney or accountant like insurance, then it is worth the costs.
The above is not legal advice and is for informational purposes only. This information does not create a lawyer client relationship.
I agree with Mitchell. If your end goal is to incorporate so that you can open up a business bank account, then I would recommend LegalZoom - much cheaper than any attorney could do. But if have more complicated needs, you should plunk down some money for a proper operating agreement / charter.
Believe it or not, doing the initial incorporation is not particularly expensive as far as legal costs are concerned. The bulk of the expense in getting incorporated are from state filing fees and notice publication requirements (if required in that state). You don't even "need" LegalZoom to do it (for example the New York State Department of State provides a fillable form that you can submit along with filing fees and PRESTO! you have an entity)
Where the cost starts to come in is when you start needing more complex incorporation documents.
A one-size fits all Operating Agreement just simply doesn't work for a multi-member LLC where everyone is bringing different concerns and perspectives regarding ownership and the relative value of contributions.
A corporation's bylaws or certificate of incorporation can be drafted in ways that protect the founder from later intrusion and meddling from outside investors. Depending on what you want, a good attorney can help you create an entity that is rigid or flexible.
Remember that fillable form I mentioned before? It only has three provisions in it. My standard single member LLC Articles of Organization have eight to twelve. Sure, you can DIY, but you may not be as protected as you should / could be.
Understanding what you want and then figuring out the best way to approach it is the province of a good attorney. Incorporation is just the beginning. When you create a business, especially if it is successful over time, you will need the counsel and service of a trusted advisor who knows and cares about you and your business. We owe you a duty that LegalZoom and paper factories do not.
I suggest consulting with a few different attorneys and working with the one you determine to have the best mix of qualification and relatability. You need to have a lawyer that cares about you, that you can trust and build a relationship with.
The start-up phase is the foundation of your business, build it with strength. If costs are an issue (as they usually are with a start-up) have that conversation and try to work something out. Capital is always an issue for start-ups, and start-ups almost invariably NEED the advice and counsel of professionals. It may be hard to see professional's fees as anything other than a cost in the short-term, but in reality they provide long-term value.