Details, Source and Flavor
Your instance must have a name; a description is optional. In certain circumstances you deliberately choose the Availability Zone, but you can also let Nectar decide by choosing Any Availability Zone. You can launch multiple instances at a time by setting the Count
Choose a Boot Source (most common is Image)
Use the Filter widget to help you find the image you need; Use the up-arrow button beside the image you need to select it for launch
If you started the Launch dialog from the Images page, instead of the Instances page, the Source tab is already configured right. If you need to, you can make changes.
A quick word on Filters: Throughout the Nectar Dashboard you’ll find filters to help you find images, flavors, security groups, networks etc. You can type free text into filters, or build specific filters as shown in the example here
Use the Filter widget to help you find the Flavor you need
Use the up-arrow button beside the flavor you need to select it for launch