World Building help (D&D 3.5)

Alright so for a 3.5 game I'm running I'm building out a world, right now I have the first continent they're starting on all wrapped up nicely, however the first continent is not meant to be stayed on for a long time, and I need help planning out the others, (I have very little about all of the other but 1).
What I do have follows.
-7 Unnamed Continents
-2 are smaller (About Alaskas Size)
-The other 5 are all around the size of Canada
-None connect, each continent is it's own island
-They all hold multiple kingdoms

What I need help with
-Fluffing out the continents names/size/etc
-Fluffing out kingdoms (Background/area on the continent/etc)
-Fluffing out landmarks (Giant mountains/chasms/magical or supernatural oddities/anceint ruins/etc)
-Fluffing out the seas/oceans

There might be more I'm missing.

You'll probably need to give us more to go on.

Do you have a map yet?

I have a map of one kingdom, though not detailed. I'm building up the maps for the other 7, but am mainly focusing on the first.

make a mountein made out of jelly.

Do you really need all seven continents fully fleshed out to run your campaign?
I mean, does it really have an impact on the campaign story?
I´m asking because in my experience, if you try to fluff out even the most remote corners of your world, you risk losing yourself in the details.

Why don´t you focus on the region where your campaign takes place first and only develop some rough ideas for the other continents? Instead of developing every continent to the last detail you could just write down something like: "There are gnomes, elves and giants living on this continent. The gnomes are organized in an alliance of city states, the elves have three large feudal kingdoms and the giants are a nomadic culture with many competing clans."

If your players are unlikely to reach this continent in the near future, this should be all the information you need for the time being. Maybe draw a rough map with major mountain ranges, rivers and population centers and you should be set.