... select files and folders to import

With the Import command you can't. The import command can only import a single item, and that is usually a folder, imported recursively. But there is a workaround:

1. Create a new folder in the repository for your import, using repo-browser.
2. Checkout the new folder over the top of the folder you want to import. You will get a warning that the local folder is not empty. Now you have a versioned top level folder with no versioned content.
3. Use the Add command to select the bits you want to add.
4. Add items to the ignore list as required.
5. Commit the top level folder.