Note: If your video is standard definition, set your data rate to 2000kbps and your display resolution to either 640x480 (4:3) or 640x360 (16:9).
For more information and tutorials, please visit: vimeo.com/help/compression
Update 1: Yes, you can change your export resolution settings from the render out menu. However, this is where you might find unintended black bars (letterboxing) or odd pixel ratio conflicts (stretching and/ or squishing of your composition upon export). If you set your comp to your desired export settings, what you see should be what you get, in that regard.
Update 2: If you are using this tutorial for AE Creative Cloud, adding to the Render Que will not give you an H.264 option. Instead, go to FILE > EXPORT > ADD TO ADOBE MEDIA ENCODER QUEUE. When Encoder opens, upon selecting H.264 under FORMAT, click on the text under PRESET. It will open the same menu as found in Adobe Premiere Pro's EXPORT SETTINGS. Select the appropriate settings you want, click OK, that will close the EXPORT SETTINGS menu. Click on the green triangle button in the upper part of that panel, or hit the RETURN key.