Bulk importing posts using Bulk Buffer
Bulk Buffer is a free service, allowing you to upload a CSV of up to 250 posts, which would be imported into your Buffer queue. Hop over to https://www.bulkbuffer.com/ and click the Start uploading for free button. You'll be asked to authorize Bulk Buffer to access your account. Click Allow access.
Once logged in, you'll have the option to upload a CSV or add updates manually. Here's a sample CSV. Bulk Buffer will turn any URLs you include into short links, using the link shortener you've chosen for each social account. You can also include pre-shortened links in the CSV if that works better for you.
Once imported, all the updates from your CSV will be loaded on the page. Feel free to make any edits at this stage and then select which social accounts you'd like to share these updates to. Finally, click Send to Buffer.
The updates will be sent to your Buffer queue(s) and from here you can make any changes and upload images/videos to go with your posts.
A cool thing to note is that although Bulk Buffer doesn't offer the ability to include images with these updates, if you include a link, Buffer will automatically turn it into a link preview for supported social networks, including Facebook, LinkedIn and Google+ pages.
Bulk Buffer is a completely free tool and is supported by donations. If you'd like to donate (any amount) to the service, I'm sure it would be very gratefully received. You can do so by clicking on the Donate via PayPal button on the left hand side. Of course, this is completely optional!