Most editors work internally with some kind of proprietary format that manages changes made to an original. Rendering breaks that chain and so can make applying LUTs a bit faster since the application doesn't have to work against the entire edit. If it were me I'd do a rough cut to get rid of the original footage that isn't going to be included in the final and then render that out with the same specs it was recorded in. I'd then apply any color correction/noise reduction to the individual clips and when I was happy with the clips bring it all together in the finished project. What you should render to is dependent on what you want to do with the footage. There are endless articles on all the different rendering options and what they end up as and where you should start. You want to come up with a workflow that takes you from your original footage on through a finished product.
