Hi John,
your query contained several syntactical bugs; this one is probably what you were looking for:
for $x in doc('SHIST')/Searches return insert node <SH><Id>0</Id><Date>20130515 14:05:44</Date><Query>{ for $x in doc('Docs')/Docs/Doc where $x/Title[Desc/@name='IT' and Year >= '2010' and Year <= '2013'] return $x }</Query></SH> as last into $x
Best, Christian