Should my husband include me on his tax declaration?

He was unemployed 'till june of last year, he got two jobs and recently gto his w2's on the mail, while he was unemplyed i was fixing computers and getting paid in cash, and now i have a 1099 from the guy i was working with. My husband says that he doesn't want to file jointly because he fears that we'll have to pay too much... Any suggestions??? Sholud he claim me?? Should I file separately??