Was just passing by and saw your question.
I currently have an instruction that my managers responsible for products upload created for themselves, seems to work good. I've made some modifications to it for this thread though.
Here you go, it's pretty straightforward:
1. Unzip the Magmi archive you've downloaded and upload the folder "magmi" into your Magento root directory).
Now you will be able to open its web interface by using this link:http://yourwebsite.com/magmi/web/magmi.php
(where "yourwebsite.com" is the name of your website).
2. I recommend that you close that folder with a password for security. Just google "how to protect magento web directory with password", there are many articles out there which give instructions for protection. For consistency reason I will not stop at this point.
3. Now, if you need, you're ready to install Magmi addons. Go to this page http://sourceforge.net/projects/magmi/files/magmi-0.7/plugins/packages/
and download them.
4. Once the packages are downloaded, extract them.
5. Open your Magmi web interface:http://yourwebsite.com/magmi/web/magmi.php
. You will see "Upload New Plugins" option.
6. Upload the needed plugins. Once uploaded - press "Save Profile" link at the bottom of the page (I recommend to press save after every change you make in the Magmi interface).
7. Now setup connection to your magento database, magento parameters and permissions via Magmi interface - according sections "Database", "Magento", "Global", "Dir & File permissions".
At this point you may try to start importing your products.
8. Upload the CSV-file for import via your FTP into folder:/public_html/var/importNote
: In order to import all product images automatically, you need to:
a) Go to Itemprocessor "Image attributes processor v1.0.29" (can be found in section "Itemprocessors") and tick on it. Then press "Save Profile".
b) Upload the product images into folder:/public_html/media/import/
For example, if your .csv file contains image path "/some_folder/image.png" - you will need to have a file uploaded into your FTP: /public_html/media/import/some_folder/image.png
9. To start import, go to http://yourwebsite.com/magmi/web/magmi.php
and follow the steps from screenshots Magmi_manual_1.png, Magmi_manual_2.png (attached).
10. That's it, your import is completed!
Hope this manual helps save time to many others out there. Enjoy
P.S. in case someone has any better ideas than I do - feel free to post below.