1. There are descriptions in the Bible of Heaven being a large, jewelled city, where there is no sickness, no strife, and no lack of anything we need.
2. Marriages are only valid until death parts the husband and wife, and so there are no marriages in Heaven. Since God created sex for mutual enjoyment and procreation within a marriage, there will be no sex.
3. But this said, in Heaven, we will have new bodies that are not the same as they are now so we will not feel a lack. I think we will still be our own genders, because one's gender is determined by more than just body parts. I haven't thoroughly read up on whether or not our genders will remain. Angels are non-gender though, (or perhaps an entire gender of their own) and therefore unable to reproduce.
4. Good deeds do not determine whether or not people go to Heaven, however the Bible teaches that those who believe in Jesus will be judged for their deeds, the bad being burned away and the good being refined. What good we have done will be our reward in Heaven. But there will also be those very new to faith and perhaps not exercising faith very well, who will enter Heaven "as those escaping from the fire." They will have little or no good deeds to be rewarded for, but they will have escaped Hell, or an eternity separated from God.
Thanks for the question though! It's good to think of what it will be like. I am currently reading a book called "Heaven" by Randy Alcorn. It is a culmination of 25 years of researching every biblical reference to Heaven, which could answer your questions more thoroughly, and answer questions you haven't asked yet! God bless!