Hi Canadiense,
With InfoPath 2010, if you design the form from the list, it's easy to submit forms that become SharePoint list rows. One-to-one though - you create one SharePoint list row per submit.
If you already have a form (that was not designed from a list), or if you want to submit multiple rows per form, you will need to use code.
If you want to save time trying to figure out how to add that code, and get a bunch of other cool features, you can just try the free trial of qRules 2.2:
(Disclaimer: Qdabra has provided this free forum to the InfoPath online community since 2003. We don't make any money off of the forum, but we do sell a few tools at very reasonable prices in an effort to defray some of the cost of the forum. If you find value in this forum and you want to help support Qdabra while saving cost and time developing your solution, please consider trying out qRules or one of the other accelerators. Discounts are available if you like the free trial and want to send us a 2-3 sentence quote that we can use with your first name on our website. There are hundreds of happy qRules users and we will be releasing new functionality in v2.3 soon. Your purchase today enables you to free upgrades.)