Take pleanty of water or know that the buzzards will eat well if you don't. Trail head is actually at Poway Rd and 67. Take Rncho Bernardo from I15. This becomes Espola which dead ends at Poway Rd. Left on Poway Rd to 67.
Northeast corner is trail head.
There are two routes here. To the top of Iron Mountain or the Elle Lane loop. Either way head up toward the top. At the 1.5 mile mark you can head right to the top, or left to Elle Lane. The top and back is 6 miles, the Elle Lane loop is about 7 miles.