ok ill give it a go

the exaust gases exit the engine and are directed vire the exaust manifolt down to the turbine half of the turbo this in tern rotates the turbo shaft up to any think in excess of 150000 rpm

on the other end of the shaft is the compresser housing this then drags air (through a filter/ meatering head air flow meater ect ect ect) in the inlet compressing it and feeding it through an intercooler (due to the fact the turbo is bolted to the exaust manifold it has a tendancy to get hot hence the need for an inter cooler) then it makes its way to the inlet side of the engine

when the disired boost leavle has been reached the positive boost presure will act on the actuator (dependant on the type and how its set up ect) and will open the wastgate within the turbo exaust housing bypassing the exaust gases around the the turbine half of the turbo and directley into the exaust system to stop the turbo from spooling any more.

now talking about the "bleed valve" when the actuator starts to move opening the wastgate say its set to 10 psi for arguments sake the bleed valve will bleed some of the presure out of the feed pipe going to the actuatur so the turbo will have to work harded to get the actuator to move (hence now the boost presure has been increased)

and that i hape ancers it lol sooooooooooo sorry for my spelling lol