As you already know HST in British Columbia will come in effect on Canada Day.

If you are already collecting GST or PST or both as of July 1, 2010 you will start collecting HST.

Please make sure that your invoices clearly state amount  of  HST collected.

You will collect and remit HST based on your current GST filing frequency (i.e. quaterly, annually etc).

For more in formation on filing HST returns  and rules and regulations  please visit official CRA website

http://www.cra-arc.gc.ca/gsthst/

For  a list of  products and services that are taxable under the HST please see the following links

http://hst.blog.gov.bc.ca/wp-content/uploads/2010/05/GST_PST_HST_List_v04.pdf

http://hst.blog.gov.bc.ca/2010/03/27/rebates-exemptions/