Research Paradigm = The approach what you choose (Qualitative Analysis, Quantitative Analysis, Inductive method... etc...)

Research Strategies = The research "modus operandi". How you will get the data from your sample.

I agree with Fabio's answer above but the research paradigm could also indicate the research discipline through which you choose to undertake your research. For example you can study a country through the disciplines of economics, psychology, sociology, etc. Each discipline presents a different research paradigm. The research strategies might reflect your research method which would flow out of your research paradigm.