If you want an intresting look at how Ultron got really started, you need to read the following....
"The False Man/Hundred Heads of Ultron"(Daredevil #275-276) -- a facinating look at how other Marvel heroes(specifically a WOEFULLY unprepared Matt Murdock) see Ultron's motives, it a nice character study....
"The Great Betrayal"(Avengers #66-68)--this one bring's out an intresting question: Exactly how far are you willing to go for a loved One? The Avengers themselves find out the Awnser to that(even if the writer's weaseled their way out of it at the end imho)....