Step by step instructions on how to scan documents to my pc

In case you don't have the manual, check this online :

http://files.canon-europe.com/files/soft39530/Manual/Canon%20MP495_499%20EN.pdf

Assuming you have installed the software (from the CD-ROM) successfully, the scanning tools/program (MP Navigator EX) will guide you through the scanning process. See pp. 22-23 and pp 330-338 of the above document.

Personally, I found the Pixma manual singularly unhelpful. Through trial and error, I discovered the following process (Caveat: I'm working from memory on some of this so some specific details like the wording on buttons might be a bit off.)
1. Put first page of document on scanner with top of document to the left.
2. Find Programs>Canon Utilities>IJ Scan Utility>IJ Scan Utility (yes that is there twice on purpose) and double click on it to launch it. A little IJ Scan Utility control panel will pop up in the middle of your screen.
3. The first time you are using this utility, click on the "Settings" button on the lower right, then select "Document Scan" from the menu on the left. Most of these settings are self-explanatory (or don't need to be changed, or both) EXCEPT the "Data Format". If you *ever* want to scan multipage documents, select "PDF (Multiple Pages)" for the format here. This way, after you scan each page it will ask you if you are done or want to continue. If you pick ANY other format, you can only scan one page at a time and each will go into a separate file. Also note: Be sure to make a note of the output directory you set here. You are not given an opportunity to change it at scanning time so you will have to go to whatever directory you specify here to find your files. If you, like me, forget where you told the utility to put them, it can take a while to find them again. When you're finished with your settings, click "Ok" on the bottom right.
4. Click "Document" on the little IJ Scan Utility control panel and the utility will say "Warming Up ... Do Not Open Scanner" (or something to that effect) and then scan the page on the glass. (Note: I frequently get a warning about "low memory" but it has never caused a problem.)
5. After the page is scanned, the utility will provide a couple of buttons: "Scan" or "Quit" I think. If you want to scan another page, put the new page on the glass BEFORE clicking "Scan"; if you're done, click "Quit" and IJ will start putting the output file together. If, in the settings, you clicked "Check Results", you should see a view of your scanned document. (Sorry, I forget what happens if you didn't.)