In other days, Muslim do normal 5 Shaalah per day. Subh, Duhr, Ashr, Maghreeb, Isha.
Special in Friday Muslim (male) do Shaalah Subh, Shaalah Juma'ah (Friday prayer), Ashr, Maghreeb, Isha. But Muslimah (female) do normal 5 Shaalah.
There is a condition for Shaalah Juma'ah. You cannot do alone, but must in companion / Jama'ah with at least 40 Muslims, including yourself and not including kids. If Muslims in your place is less than 40, you must do Shaalah Duhr.
There is procedure for Shaalah Juma'ah. Khatib must says two khutbahs, one long and one short before Shaalah Juma'ah.
I hope someone can give us a link of complete information about Shaalah Juma'ah.