Mac moving so slow pages won't load

Question

HELP!!! I'm not sure what to do. My Mac has become so slow I can't properly watch video and it takes forever to load pages which often time out and crash. I don't know much about computers at all so if you respond please be very specific and detailed if you think you could help ; )
I would truly appreciate it. I have school starting on Monday and I have tons of work to do on there. Anything you can suggest will help. I'm not even sure where to see how much memory i have or ram or whatever could be full. Like i said don't know much about these things other than I don't know what I'd do without my mac!!! THANK YOU!!!
okay i have 2 ghz intel core 2 duo
and 1gb 667 MHz DDR2 SDRAM
Model Name:          iMac
  Model Identifier:          iMac7,1
  Processor Name:          Intel Core 2 Duo
  Processor Speed:          2 GHz
  Number Of Processors:          1
  Total Number Of Cores:          2
  L2 Cache:          4 MB
  Memory:          1 GB
  Bus Speed:          800 MHz
  Boot ROM Version:          IM71.007A.B03
  SMC Version (system):          1.20f4
  Serial Number (system):          W8xxxxxX85
  Hardware UUID:          00000000-0000-1000-8000-001EC20E91BA
<Edited By Host>

Answer 1

First, back up all data immediately, as your boot drive may be failing.
Launch the usual set of applications you use when you notice the problem.
Step 1
Launch the Activity Monitor application in any of the following ways:
☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)
☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.
☞ Open LaunchPad. Click Utilities, then Activity Monitor in the page that opens.
Select the CPU tab of the Activity Monitor window.
Select All Processes from the menu in the toolbar, if not already selected.
Click the heading of the % CPU column in the process table to sort the entries by CPU usage. You may have to click it twice to get the highest value at the top. What is it, and what is the process? Also post the values for % User, % System, and % Idle at the bottom of the window.
Select the System Memory tab. What values are shown in the bottom part of the window for Page outs and Swap used?
Next, select the Disk Activity tab. What approximate values are shown for Reads in/sec and Writes out/sec?
Step 2
You must be logged in as an administrator to carry out this step.
Launch the Console application in the same way as above. Make sure the title of the Console window is All Messages. If it isn't, select All Messages from the SYSTEM LOG QUERIES menu on the left.
Post the 50 or so most recent messages in the log — the text, please, not a screenshot.
Important: Some personal information, such as your name, may appear in the log. Edit it out before posting.