Stupid questions about experts' names

Hi.

Can anybody tell me how to coorectly pronounce following names? My English is quite bad to understand it.

1. How to pronounce "Snyder"? [snaider] or [shnaider] or what?

2. How to pronounce "Uston"? [uston], [aston] or [juston]?

3. How to pronounce "Grosjean"?

Thanks in advance and sorry for silly questions.