Organizing FMRI results is hard work. Perhaps that explains why the vast majority of the world's population doesn't do it, and wouldn't do it even if they knew how. Nevertheless, for a harmless drudge such as yourself, organization and interpretation of results is a daily necessity, and the more streamlined you can make it the better for you and your adviser overlord who unfortunately will not be able to fund your summer research but will be ordering that custom-made Bentley imported from England. Keep at it, and one day you'll be the one importing cars and being swarmed at conferences by more science-worshiping nerdlings than you can shake a stick at.
To help you out with this, there is a short Excel spreadsheet template that you can find here which will automatically plot a barchart of your results and calculate both main effects and interactions. This is especially useful for plotting and calculating double dissociations, which is one of the most attractive, sultry, sexy results found in the literature. According to most people, anyway. Me? I'm more of a simple-effects kind of guy. Ladies?
Hit the video in case you aren't completely sure how Excel works, and need a brief refresher. Or, if you're just curious what kind of shirt I'm wearing today.