It is difficult to say exactly how much was lost. We have some sources that enable us to say what manuscripts were held by some monasteries, for example the library at Peterborough, or that at Syon Abbey.
Many of the manuscripts ended up in private libraries, with the best often ending up in the Royal Library manuscript holding.
Wikipedia provides an incomplete list of the monasteries dissolved by Henry VIII. In many cases, a quick Google search for a particular abbey or monastery will provide a list of notable individuals known to have been buried there. A few examples would be King Edmund I and King Edmund II (Ironside) who were both interred at Glastonbury Abbey, and Richard III, whose place of burial at Grey Friars, Leicester was famously lost after the Dissolution and found again in 2012.