proper sources of Bukkit/CraftBukkit

Apparently, the general Bukkit discussion is not for Bukkit because nobody can really give answers there, so I have to ask here.
So, I'm trying to get Bukkit/CraftBukkit source code working properly in Eclipse, but I have some errors.
I have Eclipse for Java Developers 3.7M5 build, EGit and m2eclipse plugins, Maven 3 in C:\Maven\bin and added to PATH.
This is what I do:
1) Using EGit, clone the CraftBukkit repository (https://github.com/Bukkit/CraftBukkit.git)
2) Import as an existing Maven project (1 error here: )
3) wait for it to download all there is to download
this is what I get:
4) clone/import Bukkit repository (https://github.com/Bukkit/Bukkit.git)
this is what's left:

The warnings come from unparametrized raw types (ArrayList without <type>, LOTS of all collections like that for some reason - NOT cool), but the three remaining errors are what bothers me.
The first one to me seems to be a missing dependency. The other two - invalid Overrides? And nobody notices those?

Anyway, what nobody has bothered to explain is WHAT exactly is Bukkit and WHAT is CraftBukkit and what are their roles, and why do I need both (because obviously I get errors without Bukkit).

 

I have no idea how to use eclipse properly. But your import screen shot doesn't look anything like mine.

I just do File->Import->Maven->Existing Maven Projects
Then i locate where git has saved the source. There is a pom file there.

 

Check the pom file and click next, that's where I had that error. It only appeared the first time I imported a Maven project, but it's still there so...