Raster to shapefile and creating an index model

Hi all,

This is a two part question. I'm creating a EPA DRASTIC index model in GIS. I have all the data I need to perform this, just curious to know how you would go about it.

For starters, two of my data sets are in rasters.

1) my interpolated depth to water
2) slope percent

How can I convert these to a grid to be used for my index calculation?

for the index model, it assigns a value of say 1 for 0-5' ftw, 2 for 5-10' and so on and so forth. Each data set has its own index weighting, and then they are all added together.

Then for the last part, how would I go about matching up all my indexes to one another and still be georeferenced? I assume I can just do it in excel, and then link it to some sort of feature class?

Can I create a fishnet, then have each cell represent a value for a particular shapefile. Then do the same for every other shapefile, do the math in excel, and then use the result with the fishnet to display?

Thanks,
Bob