Sorry, names may not be the correct one, I'm writing it from memory, I may have forgotten the menu names.
To use grabit, you need to setup a server (given by your newsgroup provider).
Once you added the servers, you have two choices :
1) Manually checking existing groups.
- Go to the "group tab",
- download a list of existing group. then select the one you want and subscribe to it. It will add it to your "article tab".
- Go to article tab, you will see your subscribed groups there. Select one and "retrieve the latest headers".
Headers are the subject of the messages posted on the newsgroup (remember, newsgroups are like emails : subject + body + attached data).
- Once you have the header for that group displayed, you can search and download the article you want. It can be text only, or binary.
2) Using NZB files to download a specific file.
- Go to any nzb referencing website.
- Search what you want to download, select it and generate a .nzb file.
- Load this nzb file in grabit (there's a button to open/import files).
nzb contains the information of the file you want to download (like a .torrent file does), grabit will download them.
You may have to limit the download threads, as providers usually limit the amount of simultaneous download.
5-10 are fine. don't use all 30 (they are enabled by default, uncheck them)