I need a statistician

I'm looking at how rhizobia affect seedling growth and how does this vary with seed size. Some plants were inoculated with rhizobia while others were not. I have two explanatory variables: rhizobia and seed mass. I am measuring the height of the plants, the no. of leaves, the no. of flowers etc as response variables. I want do multiple linear regressions in R for each of my observations and for each of my response variables e.g. Observation 1: height with rhizobia* seedmass. I am using R, and I need to interpret the results and do the appropriate graphs. Could someone help me?