Beatmapping is the process of creating beatmaps in osu! for players to play.
This involves choosing a song, timing, placement of objects, and (optionally) skinning and storyboarding.
Mappers usually want to get their beatmaps ranked which consists of the beatmap ranking procedure.
As osu! is a rhythm based game, the song/music you choose to map should have an obvious and constant beat.
Try to avoid songs which have tempo (or speed) changes or slow songs until you are more experienced and used to beatmapping.
To make a new beatmap, go to the edit mode then drag-and-drop an audio file into osu!.
(Alternatively, you can move an audio file onto the Songs folder.)
This should open and direct you to the edit screen with your audio file.
Your new song will be available at the bottom of the song list, highlighted in purple.
If it is not listed in the song selection for any reason, press F5 to reset the beatmap cache and it should appear.
Click on the song, this will open the beatmap editor and the Song Setup dialog.
Main page: Song Setup
When making a new beatmap, you will always see this dialog before any other parts of the beatmap editor.
You should fill out this information before creating another difficulty.
This will ensure that the metadata will be consistent across all of the difficulties in the set.
You can change the options in the other tabs now if you want, but they can be changed later on.
Click OK, and you can start beatmapping!
The next step is to add timing to your beatmap.
Main page: Timing
Timing is vital!
Incorrectly timed maps will not be considered for ranking.
You must make sure that your timing is perfect before adding any hit objects.
If you are in doubt about timing, contact a mod for help first, or submit your song into the Beatmap Help forum.
This will save you (and the modding community) a lot of hassle later on.
Main page: Compose
The compose tab of the beatmap editor is where you will probably spend a majority of your time beatmapping.
It is where you can visually place hit objects and toggle their hitsounds.
Main page: Design and Storyboarding
The design tab of the beatmap editor is where you can set the beatmap's background image, add a video, and/or make a basic storyboard.
Depending on what you do, you may use the design tab a lot or none at all, if you happen to be doing SBS (storyboard scripting).