Very often the size of PDF or JPG files is too big. There are easy ways to optimize those files an reduce the size significantly. Here are some of them:
1. Open a pdf document in Adobe Acrobat
Document > Reduce File Size
It will save a copy of your document that os optimized for web.
2. Open a pdf document in Adobe Acrobat
Advanced > PDF Optimizer
You can manually reduce images file sizes by changing the resolution number. The lowest I'd go is 72 pixels/inch
Go to "Clean Up" option
Make sure you check "optimize the PDF for fast web view"
OK
Note: Just a reminder - to convert a Word document into PDF - File > Save As > PDF :)
To optimize an image:
Open image in Adobe PhotoShop
File > Save for Web & Devices...
 | You will see a window like one of these. |
 |  |
Depending on the tab that is chosen....
I like to use 4-up tab. This is where you see the original image (and its file size) and three more options of this image with different degree (and quality) of optimization.
 |  |
Compare the original file size and each of the optimized options. Decide between the smallest file size and acceptable quality. Remember that reducing the file size decreases the quality
 | You can adjust the setting manually: Make sure the JPEG is set for photographs. Choose Low, Medium or High Quality ... or use the Quality slider. Then click "Save" That's it! |
