If you want to publish pins from your computer or website you'll have to use campaigns. I prefer standard campaign.
Since you want to publish different pins on different boards, you'll have to create separate destination list for every board and separate campaign for every destination list.
Then you can start adding posts to corresponding campaigns. When you add image, add description too, then also add Pinterest Source URL - this will be the url where pinterest users will be sent after they click on image, so I guess, it's a link to your website.
Add destination list in when to publish tab and set how many posts and when to publish posts in when to publish tab. Start the campaign, you're ready to go.
For repin tool, you'll have to set up settings and add sources for each board separately. Go to tools section, click on your Pinterest account and then choose the board where you want to repin to. There you can set how many repins you want to make, sources to use and see the results.