Thanks very much Joshs. I totally agree with you that one needs some background in order to understand Derrida. I have tried to understand Derrida through his critique of Saussure as I know Saussure's semiotics very well.
with regards to relationship between reality and representation, 1) Derrida does not deny the relationship between reality and representation. This can be inferred from the quote "It is totally false to suggest that deconstruction is a suspension of reference" (Derrida 1984, pp. 123-124). Of course, the reference here should be understood as slippery and indeterminate reference given differing and deferral rather than a simple and transparent reference.
There are other related questions. Say, what does Derrida say about reality? I mean what is his ontological view?