Video/Audio recording bleg.

Basically: if I want to keep decent sound quality for my phone interviews I need to stop converting them into MP3 format. Unfortunately, I am not exactly a sound engineer, so I don’t know what the alternatives are. I want to mostly keep the audio files on this site, which gives me a single-digit MB limit per file (which I don’t really want to adjust); what format should I be using, and what editing software.

Also: I need something better than Movie Maker for my YT files. I know, I know: evergreen complaint.