No problem. :]
The lowest level of paradise will be for the people who believed in the oneness of Allah, but were tempted by this world. So they completely believed in the message of islam, Allah, the prophet, etc. but they had lots of sins. They would spend a certain amount of time in hell, and then be admitted to paradise.
Muslims believe that when the prophet muhammad :arabic5: came with the quran, all the books previous religions before him (Judaism and Christianity) were annulled, because they had been changed by humans, and were no longer in their original divine form. So a christian or jew must follow islam to enter heaven, since it is the last and only unchanged message from Allah. The prophet :arabic5: said: "Anyone of this Ummah, whether a Jew or a Christian who heard about me and died without believing in what was revealed to me, he will be among the people of the Hell-Fire"
Here's an authentic hadith about the very last person to enter paradise:
"Reported in Sahih al-Bukhari, the Prophet (salAllahu `alaihi wa sallam) said:
Some of the people will stay in Hell (be destroyed) because of their (evil) deeds, and some will be cut or torn by the hooks (and fall into Hell) and some will be punished and then relieved. When Allah (subhanu wa ta'ala) has finished His Judgments among the people, He will take whomever He will out of Hell through His Mercy.
He will then order the angels to take out of the Fire all those who used to worship none but Allah from among those whom Allah wanted to be merciful to and those who testified (in the world) that none has the right to be worshipped but Allah. The angels will recognize them in the Fire by the marks of prostration (on their foreheads), for the Fire will eat up all the human body except the mark caused by prostration as Allah has forbidden the Fire to eat the mark of prostration. They will come out of the (Hell) Fire, completely burnt and then the water of life will be poured over them and they will grow under it as does a seed that comes in the mud of the torrent.
Then Allah will finish the judgments among the people, and there will remain one man facing the (Hell) Fire and he will be the last person among the people of Hell to enter Paradise. He will say, 'O my Lord! Please turn my face away from the fire because its air has hurt me and its severe heat has burnt me.'
So he will invoke Allah in the way Allah will wish him to invoke, and then Allah will say to him, 'If I grant you that, will you then ask for anything else?'
He will reply, 'No, by Your Power, (Honor) I will not ask You for anything else.'
He will give his Lord whatever promises and covenants Allah will demand.
So Allah will turn his face away from Hell (Fire). When he will face Paradise and will see it, he will remain quiet for as long as Allah will wish him to remain quiet, then he will say, 'O my Lord! Bring me near to the gate of Paradise.'
Allah will say to him, 'Didn't you give your promises and covenants that you would never ask for anything more than what you had been given? Woe on you, O Adam's son! How treacherous you are!'
He will say, 'O my lord,' and will keep on invoking Allah till He says to him, 'If I give what you are asking, will you then ask for anything else?'
He will reply, 'No, by Your (Honor) Power, I will not ask for anything else.'
Then he will give covenants and promises to Allah and then Allah will bring him near to the gate of Paradise. When he stands at the gate of Paradise, Paradise will be opened and spread before him, and he will see its splendor and pleasures whereupon he will remain quiet as long as Allah will wish him to remain quiet, and then he will say, 'O my Lord! Admit me into Paradise.'
Allah will say, 'Didn't you give your covenants and promises that you would not ask for anything more than what you had been given?' Allah will say, 'Woe on you, O Adam's son! How treacherous you are!'
The man will say, 'O my Lord! Do not make me the most miserable of Your creation,' and he will keep on invoking Allah till Allah will laugh because of his sayings, and when Allah will laugh because of him.
Allah will say to him, 'Enter Paradise,' and when he will enter it, Allah will say to him, 'Wish for anything.' So he will ask his Lord, and he will wish for a great number of things, for Allah Himself will remind him to wish for certain things by saying, "(Wish for) so-and-so.'
When there is nothing more to wish for, Allah will say, 'This is for you, and its equal (is for you) as well.'
Abu Hurairah said, "That man will be the last person of the people of Paradise to enter Paradise."
Here's a link that describes what I talked about some more:
PARADISE
As for verses from the quran, it doesn't go into details about the different levels of paradise much, but here is a description of paradise in general that quotes many many verses:
DESCRIPTION OF PARADISE