Load up photoshop so it looks like this
I have Adobe cc so it will look different than if using a different cs version
Click on FILE at the top left hand corner of your screen
Manoeuvre your mouse down the FILE menu until you come across IMPORT.
Then mouse over to VIDEO FRAMES FROM LAYERS
Your file folder will pop up and that's where you select the video you want to turn into a gif.
Once you have your video selected click on open
A window like this will appear: Do not be afraid!
The arrows on the side of the timeline look like this
Use them to shrink the size of your gif, This allows you to pick the exact part of the video you want to be gif'd.
then click on OK
TIP: Photoshop will limit you to 500 frames so be careful with how big your arrows span
Once you hit OK your screen will appear like such
Before you get overwhelmed click on WINDOW at the top of your screen
Mouse down on the menu to TIMELINE and click it
Make sure it has a checkmark next to the word TIMELINE and the timeline actually shows up like in the photo above.
Now you have a basic outline of a gif! You can toggle the PLAY button which is underneath the frames in order to stop or play your gif
if you enable your timeline and it looks like this
Don't be afraid. Just click on the three boxes in the left hand corner to toggle timeline to the timeframes
Continue Learning in Making Your Gif