Disjunctive pronouns are used independently of the verb.  They are the pronouns which follow prepositions, or show emphasis.  They can also be found in exclamations.

Vengo con te.  I'll come with you.
Amo te, non lui.  I love you, not him.
Fortunati voi!  Lucky you!

Ci (there, it, about it, of it) and ne (some, of them, of it) are both pronouns that go before the verb and they replace prepositional phrases.  Ci will replace phrases that begin with in, on, to, at, under, etc. and ne will replace phrases that begin with some or a number.  

Quante caramelle hai mangiato?How many candies did you eat?
Ne ho mangiate quattro.I ate four of them.

The pluperfect or past perfect tense corresponds to the English "had + past participle."  It indicates an event that happened prior to another event in the past.  It consists of the imperfect of avere or essere (whicheer auxiliary verb the main verb takes in the past indefinite tense) and a past participle.

L'avevo già notato.  I had already noticed it.
Ero andato ad un suo concerto.  I had been to one of his concerts.
Non avevo avuto ancora occasione.  I hadn't had the opportunity yet.
Erano già stati a Sanremo.  They had already been in Sanremo.