Help me out.

[OnlineKiller-V1]

What is the charge button? When I see the command list it shows me a picture of a red circle with the word charge infront of it and with a arrow pointing left. I'm trying to do moves with other characters but I need to figure out what that charge button is.

Also for the ultra combo,what are those letters there? HML? can you explain this to me guys. These is my first sf game and I need some help. thanks

[Jaime]

"Charge" is not a button. When you see a reference to charge, it means that you need to hold the specified command for two seconds.
For example, let's say that you are playing with Blanka and want to perform his Rolling Thunder Attack. You would need to do this:

Charge , then + Punch.

The charge means that you need to hold left for two seconds, then quickly tap right and the punch button.

As for the HML, it means Heavy + Medium + Light (Punch or Kick) at the same time. You don't need to press the three buttons together though, there is a button that does the HML function (L1 for HML punch and L2 for HML kick).
You can also reassign those buttons if you feel uncomfortable with the L1 and L2 buttons.