Selecting multiple objects in Illustrator is essential to productivity. Illustrator has some great selection features: Select Same, Select Object, Magic Wand, and so on. One selection feature that I always use is Save Selection. I usually save selections early on in a illustration to easily come back to them even though the stroke, fill, and other attributes have be modified.
First, select everything that you want to save and then go Selection > Save. In the Save Selection dialog you can name the selection whatever you want. Now your saved selection will be accessible at the bottom of the Selection Menu! You can rename and delete these Saved Selections by going Selection > Edit Selection to bring up the Edit Selection dialog.