Hi Sharon,
I assume you mean singleplayer maps. Most of the maps posted on the forum as multiplayer, and most of them are already included in the KaM Remake. If you just want to build without fighting you could start a multiplayer map with only yourself in the lobby.
However, if you are looking for singleplayer maps you should visit my map site:
http://lewin.hodgman.id.au/kam/index.ph ... r_missions
It was made for KaM (before the Remake existed) so the instructions don't work in the Remake. To install the map in the Remake make a new folder inside the Maps folder of the KaM Remake installation. Give the folder the name of the new map. Then copy the .map and .dat file you download from my site into that folder, and give them EXACTLY the same name as the new folder you made.
So if the map was called "battle" you would end up with this:
Maps\Battle\Battle.dat
Maps\Battle\Battle.map
and then you should be able to play it from the Single Maps menu. We don't support custom campaigns yet (we will in the next version) so for now you have to install each mission separately.
As far as top maps, there's no top 10 map list to my knowledge but you can look at the rating and reviews on the mission site. The Dark Lord's campaign "The New Lands" is meant to be very good

For top multiplayer maps look at the number of times each map has been played on our website:
http://www.kamremake.com/servers/
Cheers,
Lewin.