I just completed my S-Corp. in early January... mostly on my own. You
can download the forms you need via the US Govt. website to obtain
your tax ID numbers, both state and local.
You need to file/apply with your secretary of state....
reserve/register a business name as well.
It is fairly uncomplicated, just time consuming to change your
accounts and paperwork to all INC.
Separate for ALL personal too.
If you're going to have "shareholders" other than yourself or have
employees as partners I strongly suggest you use an attorney.
Otherwise, you will be fine doing it yourself as long as you are
completely honest with all of the that you submit. And
it's not very expensive to do on your own either : )