I started an online web business in October last year.... I input household expenses of just over $4000 i am not being credited anything towards home expenses.

The amount you can deduct for business use of home expenses cannot be more than your net income from the business before you deduct these expenses.  In other words, you cannot use these expenses to increase or create a business loss.  However, the amount you cannot deduct this year because of this restriction can be carried forward to next year.  For more info, please see http://www.cra-arc.gc.ca/tx/bsnss/tpcs/slprtnr/rprtng/t2125/ln9945-eng.html

Thanks for your reply. for the purposes of turbo tax do  i enter in household expenses for the full year or just from oct-dec when my business started .... i wasn't sure if your program accounted for  a partial year in its calculations

Just enter the expenses from the time you started your business...Oct-Dec