The easiest way is to make an action.
You open one image, make a new action called say for web (or whatever you like) start recording the action, make the ajustments to the one images, when you have finished you stop recording the action
Now you have the action made you can either simply run it on each image one at a time (if theres a few to do at a time say) or if theres lots use the batch action option and do a whole folder full at a time (the action repetes the steps taken when it was recorder)
You can also make a droplet (desktop icon sort of) you just drag a folder of pics to it and it applies the chosen action.