OOo has only one way to automate the creation of labels: you can "merge" data from a database into a Writer document that sserves as a template for the labels.
The database can be a spreadsheet, but it must conform to the basic structure of a database table. I.e., all data that belongs together--that pertains to the same thing--is stored in exactly one row of the table, and each column in the table holds data of the same type and describing the same attribute.
E.g. if each row pertains to one label, you might have: Column A: Item Name, Column B: Customer Name
Then you can set up a label template in Writer and merge in the data, one row providing the data for one label.
You can find a good introduction to making labels in OOo here: http://www.freesoftwaremagazine.com/articles/mail_merge_openoffice_org