I do this all day. I don't know what's your knowledge level on SSIS, so I would assume it's basic.
use data flow task in SSIS. Under "Data Flow" tab, drag Excel source and OLE DB destination. Make connection to your excel file and database in Connection Manager. Make sure you are using excel 2003 sheet, It doens't recognize Excel 2007. In Data Flow tab, double click on excel source, slect appropriate connection, and then sheet. Click on Columns and check the columns you want to transfer. Take the green arrow and attach it the database destination task. Double click database destination task. Here is what's important, make sure you check "keep null values." Select correct database connection and the table. Its better to create the table here, becuase it creates the table by taking column names in your excel file. Also, make sure your column with null values isn't set as primary key. Then, execute the ask and you should be golden.