just insert a blank DVD-R, wait for it to appear on the desktop. Answer "Finder" to the question.

Take your folder and drag it onto the DVD icon that is now on the desktop.

A DVD will hold about 4.6 GB of data. Make sure you pictures in that folder are no bigger than that.
Right click on the folder and select Get Info, or single click the folder and from the menu bar, select Get Info.
If the folder size is below 4.6GB, you will be OK, otherwise you will need more DVD's and need to remove some pictures until the size comes down.

Right click and select Burn
Drag the icon to the trash bin. You will be asked if you want to burn the disk. Say Yes.

That's all there is to it