Online shoppers will spend $38.5 billion during the 2010 holiday season, up 14.2% from $33.7 billion last year, according to eMarketer, a research firm.

In a report released this week, eMarketer says that online sales during November and December will represent nearly 24% of all online retail sales this year. The research firm projects that online consumers in the United States will spend $162.4 billion this year, up 12.7% from 2009.

Online holiday sales plunged 7.9% in 2008 as the recession kicked in but are set to increase for the second straight season, eMarketer says. Online sales increased 16.6% for the 2009 holiday shopping season. The research firm predicts that Black Friday, the day after Thanksgiving that traditionally lures masses of shoppers to bricks-and-mortar stores, will increasingly become a day for online, not offline, shopping.

“Savvy consumers, knowing that retailers are posting some of their Black Friday deals online, will shop the web on Black Friday to avoid crowded malls, find bargains and locate unusual or popular items that were unavailable in stores, rather than rise early to face crowded stores,” says Jeffrey Grau, eMarketer’s e-commerce analyst who wrote the report.