Dissimilar Weld

Easy. You can google for more if these are not enough.

Key is to follow the electrode instructions as you will find some require a bit of preheat on the A36, some don't. Some depends on your materials and shapes also.

http://www.bhelectrodes.in/stainless-steel-welding-electrodes.htm

http://www.ornl.gov/info/reports/1962/3445605487826.pdf

http://www.esab.ch/de/de/support/upload/XA00048720_Stainless-handbook.pdf

http://xa.yimg.com/kq/groups/22734920/1908531984/name/Welding

preheat A36, PWHT depends on material thicknesses and your selected electrode.

Here's a link to a similar question: http://cr4.globalspec.com/thread/76237

You can also Google 'how to weld HK 40'. You don't mention size or thickness, but you will probably have better results by pre-heating.