If you use VueScan as your negative scanning software — and you should — you will have seen an option on the Color tab to select a negative vendor, brand and type. It’s almost always easy to figure out the vendor (Fuji, for instance). But the brand and type are not always obvious (something like Super G second generation 400 speed).
What you need is a reference chart that lists the film vendors, brands and types you are likely to encounter. The manufacturer of VueScan has put together a handy table that does exactly this.
The chart is fairly straightforward. For example, you may see small type on a negative such as “KODAK CP 100 5094.” This chart will tell you the negative is Kodak KODACOLOR VR 100 Gen 1, which is the information you need to use in VueScan.