Put your bag of grain when you turn on the burner. Get the water to 155 then turn off the heat and let it steep for about 30 mins. Turn the heat on after the 30 minutes and then pull the bag out and pour some of the water over it a few times (this is called sparging your grains). Then remove the grains and bag.
I would add my DME at thus point so it can be dissolved before you start to boil. This just seemed to reduce the risk of a boilover...for me it worked. Other will say add the dme once your boil starts.
After the above, you're boiling so add your hops according to your schedule.
Remember... Relax, don't worry and have a homebrew!