You don't need to steep specialty grains, you just mash them with the base grain. The general rule of thumb is:
156F - Full Body (slight residual sweetness/extra malt character)
152F - Medium Body (balanced malt character)
146F - Light Body (dryer beer/light malt character/forward hop character)
Also, to hit these mash temps, the strike water needs to be 7-8F higher than those temps so that the temp regulates back to those temps when you dump in the grain. There are plenty of calculators online to get this number exactly right, just google search for them.