Welcome and thank you for your question!
Obtaining an employer tax ID (or "EIN") is a relatively simple process that can be done by completing a Form SS4, either in paper, or as the preferred method, on-line. Here is a great link to the IRS website with information about when and why you would need an EIN, as well as how to apply on-line.
Once at this website, click "Apply for an EIN on-line" and it will guide you through the step-by-step process. Note the hours of operation are Mon-Fri 7am to 10pm.
If you have trouble with the link, simply go to www.irs.gov, and type "obtain EIN" in the search box.
Regarding the retirement plan, if you decide to form your own business, you may want to consider something called a SEP (Simplified Employee Pension). A SEP is available to any size business and is easy to establish by adopting Form 5305-SEP. For 2012, contribution limits to a SEP-IRA are the lesser of 25% of the employees compensation or $49,000. Therefore, if your compensation through your newly formed business was $196,000, you could contribute $49,000 to the SEP-IRA. There are pros and cons to adopting any retirement plan, and I would advise reviewing some specific research prior to making your decision. Factors to consider are the size of the business, both in revenues and profit, number of employees, and compensation structure.
Here is a useful link to provide you with more information on a SEP plan:
Another great resource is Publication 4333, "SEP Retirement Plans for Small Business". http://www.irs.gov/pub/irs-pdf/p4333.pdf
A slightly more detailed and technical research guide is IRS Publication 560, "Retirement Plans for Small Business":
As far as companies to manage the funds, yes Vanguard has a great reputation as a conservative and well run company. I can't speak for everybody, but none of my clients that use Vanguard have ever complained about them.
I certainly hope this has provided you with the guidance you were looking for today and as always, I am more than happy to help.