Open Finder by clicking its icon in the dock.
Select the files you would like to create a zip archive from. You can select as many files as you like.
To select multiple files either drag a box around the files you would like to select or hold down Command while you click each file.
Once you have selected all the files to be included, hold down the Ctrl key then click one of the selected files.
From the popup window that appears select Compress Items. If you have more then one item selected it will say Compress 2 Items and so on.
A popup window will appear showing the status of the compression.
A new zip archive will appear in your Finder window. Mine was called Archive.zip.
To rename this archive click to select it then press enter. The filename will highlight in blue. Type the new filename then press enter again to save it.