Hello
You can use standard Import/Export functionality that has 'Check data' option that monitors if in the file are are all the required fields.
You can also for example set products' status to disabled in your import file.
After goods are uploaded and verified, you can filter our and select your newly uploaded products to mass update them via:
Actions -> Update Attributes -> Submit
and there set 'Enabled' for Status field of selected goods.
In case you would like the solution that allows to work with your database offline you can use Store Manager for Magento. Using it you can importing goods to the local copy of your database and then if everything is ok, to your live database (with bridge type of database connection) . If you are interested, you can download free 2-week version with full access to all features.