My background is as a military shooter so I'm partial to the standard E-type silhouette.
While many will immediately respond with "Bullshit! That's way too big! Aim small, miss small!" my experience as a military trainer has been to teach using crawl - walk - run methodology. I'll show you first; teach you; coach you through it; then train and evaluate you. If you can't hit the target or see where you're making left-right errors you're wasting time and money and not learning anything (either through positive or negative feedback).
A military E-type silhouette is roughly 40 inches tall and 20 inches wide -- giving you a 4 minute of angle elevation fudge factor for ranging at 1,000 yards and a 2 MOA wide target to allow for minor wind call errors (at 1,000 yards). As you walk further back from your targets your miss error margin becomes smaller as bullets lose velocity and time of flight increases (and effects of weather have increasing influence on your math and estimates).
You can get by either shooting only at the head (a 1 MOA target at 1,000), or give yourself a little extra error allowance by going to an IPSC target. I am very partial to Ryan's Big Dog Steel Targets (a site sponsor).
