When you're just starting to make a server, you will definitely need WorldEdit for the spawn.

And, to stop people from griefing, you'll definitely want WorldGuard.

Everytime I run a server, no matter what it is, I always use those two and 'SideKick'. Apparently 'Essentials' is better but I'd rather just use SideKick.

I would say the following:

PermissionsEX (Or some other permissions system)
You will need some form of permissions to manage who can do what - using default OP permissions cn sometimes allow people to do things that you might not want them to do.

Logblock
This is an absolute necessity if you want to prevent people from griefing. It will log all block edits into a database so you can see exactly who griefed where, and when.

Worldguard (May require WorldEdit to work)
If you have a spawn area, then it's essential to region off areas where you don't want people to build. Worldguard is probably the most advanced at doing this.

As for other plugins, it depends on what type of server you want to have. If you're doing survival, then NoCheat (Or whatever is the modern equivalent) is also essential, as it will stop most functionalities of grief clients.

Essentials suite.
WorldEdit
WorldGuard
PermissionsEx
CoreProtect

These are the bare minimum I would suggest on a server.

you will need

Groupmanager Its the easiest Plugin to use

CoreProtect rollback dem griefers

Essentials