In Hamlet, please provide examples of important imagery, symbols, or allusions in Claudius's soliloquy, Act 3 scene 3i am having a hard time...

This is Claudius's only significant soliloquy in the play
and in it he reveals his guilt over what he has done.  For the first time we hear from
him how he feels about his actions.  He clearly recognizes that he has committed a
terrible sin and he would like to be forgiven that sin, but in the end he knows that if
he doesn't give up the gains from that sin (the throne and Gertrude) then he will never
be forgiven by God. 

Here are two quotes that have
several of the literary devices you are asked to
consider:

What
if this cursed hand / where thicker than itself with brother's blood, is there not rain
enough in the sweet heavens to wash it white as
snow?

In this quote there are
a couple of things to notice.  The image of the thick blood of his brother is very
powerful.  The "thick" makes it heavy and vital and the fact that it is thicker than his
hand suggests an overwhelming amount of blood.  Blood is usually a symbol of life.  In
this case it is spilled blood, and therefore symbolic of a loss of life -- King
Hamlet's.  It is also an allusion to Cain's murder of his brother Abel from the Bible. 
This is traditionally considered the first murder -- these are the children of Adam and
Eve.

Rain is usually symbolic of cleansing -- both physical
and spiritual.  Here it is a symbol of heavenly cleansing, or God's forgiveness.  He is
thinking that there is not enough forgiveness from God to cleanse him of his
sin.

He later uses hand imagery again.  He
says,

In the
corrupted currents of this world / Offense's guilded hand may shove by justice / And oft
tis' seen the wicked prize itself / Buys out the
law.

Here, Claudius is
calling his hand gilded which means it is covered over with a thin layer of gold (but
what is under the surface is considerably less worthy or valuable.)  What he really
means that he is now has all the power of the kingdom because he is king (the "wicked
prize", and as king, he will likely get away with his crimes because no one will dare to
suspect him and charge him with the crime.  In this case, no one knows that a crime even
took place, but perhaps that is because no one dared to investigate the story.  His gold
hand was able to shove justice away from his guilty acts.  The strong imagery and
symbolism again come into play in order to illuminate Claudius's
guilt.