In general, unless tenants are very cooperative and allow the home to be shown with a minimum of 24 hours notice and keep the home in "show" condition, it is better to have the home vacant while on the market. With that said, in the current market, marketing times are taking longer, you need to think about how long you would be willing to carry the property without a tenant.
Another option, would be to offer the tenant a reduction in rent during the time the home is on the market as an incentive for the tenant to cooperate with showings.
Without seeing the property and doing a walkthrough, it is difficult to provide you with a price for your home. When you are ready, I would welcome the opportunity to provide you with a market consultation.