You can access cookbooks on a network drive in the same manner explained below with online drives.
Create a folder in Dropbox or Google Drive on your computer by installing their apps on your computer. See their instructions and documentation. You might also want to consider using their manual sync instead of always running automatic sync, especially if you have a limited data plan and don't want files synced each time a change is saved. This applies to other programs and files like Word document files, etc. This way after you are done making changes to a cookbook in one sitting, you can manually sync at that time when you are finished.
Open the Dropbox or Google Drive folder on your computer. Create a new folder in here called Cookbooks or something else. Add your MasterCook cookbook files (MC2 and MCX) files (and menu files too) to this folder on your computer. MasterCook does not care where you store your cookbook files on your computer. See this article for further info: Adding Cookbooks to MasterCook.
Start up MasterCook and go to the Cookbooks screen. Select Manage Collections from the Tools menu. Select this folder that contains your cookbook files. Press the ADD button. Do this for each computer that has MasterCook installed and you want to access those cookbooks. You can even create a shared folder for use with your friends who have MasterCook, and they can add that folder to MasterCook by using the Manage Collection window as well.
Caution: When using online drives note that changes to the files are stored on your computer and then synced into the cloud by Dropbox or Google Drive, etc. Therefore, you might want to be cautious about two or more computers trying to access and edit the same cookbook file at the same time. The same would apply if more than one computer was trying to access and save changes to the same Word document file. It's best if just one person works on the file at a time and then the app syncs those changes to the cloud so they can be pulled down into another computer, etc.
Otherwise, if you want to access your recipes from a device that doesn't have MasterCook you can either (1) upload your recipes to MasterCook.com so you can access them from your account there or (2) export your recipes as text and place that text file in your Dropbox folder or (3) print your cookbook to a PDF and upload that to your Dropbox folder.
To export your recipes as a text file use the Export and Mail command from the File menu in MasterCoook. Use the Text Only export setting and save it as a single file.
To print your cookbook as a PDF file download a free PDF creating program such as doPDF, Bullzip, CutePDF Writer, etc. from the internet. They install themselves as a printer on your computer. When you select them to print something, they create a PDF file instead.