Good evening. Others are correct here in saying to always take your photos at the highest resolution/finest settings that you can and use a post program to minimize physical and file size. The attached photo is about 110kb but originally started out about 3 megs from my Digital Rebel XT.
I use a very simple photo program called Slowview 1.0. If you Google it up you'll find a million places to download it. It's adware and spyware free and it's a free program. Download and install is simple and straightforward. You can choose what you want to see in the toolbar, and what sort of filetype you want to save in. (It will always open to the last file you opened in and save to the last location you saved but you can browse to any location.) You'll find a couple other settings that will make it easier and you can adjust, resize, crop, sharpen, etc with very little headache.
I have used versions of it since its inception and always load it on computers that I build/repair for others. It's a great free alternative to a pay program or hot software.
Good luck with it all...
Bob