Facebook’s initial public offering is the largest Internet offering ever. But the average investor may want to sit on the sidelines and not make history. Here is a look at the ins and outs of the IPO.

Q: Can I buy shares of Facebook on the first day of trading?

A: With all but the richest and most exclusive investors locked out of buying the pre-IPO shares, the average investor is relegated to buying shares on the open market. An online brokerage account can be the cheapest way to acquire shares, but there are market rules that govern how and when orders are placed.

Q: Who got shares in the IPO?

A: The famous and the rich. Facebook’s Chief Executive Officer Mark Zuckerberg and several early investors in the company sold stock. Zuckerberg was expected to sell about 30.2 million shares. Meanwhile, Facebook’s 33 underwriters, including Morgan Stanley, JPMorgan and Goldman Sachs, gave rights to buy shares to their most important institutional investors. Some online brokerage firms, which cater to traditional investors, required clients to have as much as $500,000 in their accounts and trade as often as 36 times a year to qualify to get shares. In total, Facebook’s offering sold 421.4 million shares.

Q: Will Facebook’s stock rise in its debut?

A: Probably, experts said. “It will go up. There’s never been an IPO hyped like this. There’s a lot of emotion around it,” said Francis Gaskins, president of the IPO research site IPOdesktop.com. “People treat it like a religion.”

Q: What will the price be on the first day?

A: Shares of Facebook are priced at $38 a share. The stock will likely surge in initial trading, following offerings of other hot companies such as Groupon Inc., Zynga Inc. and Pandora Media Inc. Those companies are now trading below their initial prices.

Q: Should I buy shares on the first day?

A: Although Facebook’s stock could jump at the opening because of the frenzied interest, experts said it won’t be a good risk. “The valuation is so high, it offers very little upside,” said Jay Ritter, professor of finance at the University of Florida and a specialist in IPOs. “It’s too late. Facebook has already made money for its private investors. For public investors, the price is starting out too high.”

Q: What are Facebook’s longer-term prospects?

A: “I don’t think it’s a good long-term play,” Gaskins said, citing reasons such as the youth and inexperience of 28-year-old CEO Zuckerberg and the recent decision by General Motors Corp. to pull its advertising from Facebook. Ritter said the expectations for Facebook are so high that its stock will be vulnerable if the company fails to live up to them.

Q: Where will Facebook trade?

A: The stock will trade on Nasdaq under the symbol “FB.”

Q: How much will Facebook be worth?

A: As much as $104 billion.

Q: How will the IPO change Facebook?

A: As a publicly traded company, Facebook will have to disclose its financial results and its executives’ compensation. It also will have stock to use as currency to buy other companies in acquisitions. It recently paid a mix of cash and stock for its $1 billion acquisition of the photo-sharing site Instagram.

– Staff Writer Jessica Hall