Thinks the best way to creat a new material is :
-Apply an existing "near" material to your item ( e.g. if you want to creat a steel /select and approaching steel il showcase existing materials )
-Modify that material with Ctrl + M
For the parameters ... i can't explain it her ! it is not very difficult, but it completly depend of the material you want to creat.
For the bump ... you can use a lot a software
nmapgen free but note really usable according to me
crazybump is one of the best but it's not free. (30 day trial if i well remember)
http://www.crazybump.com/ or making internet research (but don't type "bump" into goole
😛 --> "Normal map" is a better research )
Hop it help