i have recently come across text which adds さん to places. For example, bookstore is ほんやさん. Is this normal, and in what context?
ほんやさん usually means "bookstore owner/worker", but CAN mean the store itself. Adding さん like that to a business name is a common way to refer to such. ほんや = bookstore, さん referring to the person.
On the other hand, mountains are often referred to, ending in さん, and still refer to the place, eg ふじさん = Mt. Fuji. However, this is NOT the same さん. In ほんやさん, the さん is the person-name-honorific さん; in ふじさん, it is 山 with a reading of さん. These usages are not related.
Edit: Sorry, apparently, with さん it can STILL mean the place. AFAIK it does more often refer to the person, but you'll have to divine it from context to be sure.