What to include in my sitemap if?

I am rambabu working in an IT company as an SEO Executive. Currently working on a big project Indian Fashion Apparel site name is glitterdesignz.com I have created sitemap but i am little confuse what to include in there if website has huge number of products in its top categories, some products are adding & some are taking off from the categories list. So my question is this should i include those product pages also which are removed or adding by every going days. Please tell what should i do in terms of getting most of the crawlability benefits from the Big Search Engine like Google.com & Yahoo.com . . . thanks in advance