The tosyl group does not have much to do with the chemistry of sulphur compounds. Its utility lies in the fact that tosylates are electrophylic and the tosyl is an excellent leaving group. An tosyl ester has similar properties as an alkylhalogenide. It is even a better leaving group than a iodide, hence it is called a psudohalogenide group.
So start your search with these basic keywords:
tosylation, electrophilicity, nucleophylic substitution, pseudohal(ogen)ides ...
also
http://www.public.asu.edu/~iangould/331/handouts/nucleophilicityetc.pdf (http://www.public.asu.edu/~iangould/331/handouts/nucleophilicityetc.pdf)