I don't know about tutorials but you can probably find a few decent links with the forum search.
To save an edited file, click on "File" (along the top of the screen) and then click on "Export...". There you can set the options for the kind of file you want to make (directory, file type, file size, etc) and then click the Export button to save it.
Once you get the hang of the settings you can make a preset of your favourite settings and use that directly from the File menu, e.g. I have a Flickr preset that turns my RAWs into a sRGB jpg file with 1024 pixels on the longest side and saves it in a certain folder ready to upload.