If you are new to firearms & the shooting sports, I suggest a new or NIB: new in box .38spl revolver or .357magnum medium frame or small size. Good models include the S&W model 64, the 686+(7 round), the Ruger GP100(the new Talo model is a great buy), the Ruger LCR or a S&W model 442 or 638 .38spl.
A DA only(no cocking or hammer spur) semi-auto pistol could do okay too but a 3"/4" barrel revolver would be better.
For top semi-auto pistols, see; the S&W SD9 or SD40, the Walther PPX in 9mm(9mm Luger) or a .40S&W. The SIG Sauer P224 DAK, the P290RS 9x19mm with SIG laser add-on or the P226R/P229R DAK(Double Action Kellerman) .357sig or .40S&W. The Beretta PX4 C(constant action) is a good value. It's available in 9x19mm & .40S&W.
For defense or home protection, I like the .40 or .357sig. The .357sig feeds well & it's fast(high vel).
Know & understand the firearm and use of force laws/ordinances. Get good skill training from a top rated program or teacher. New gun laws & the huge increase in concealed carry/firearm ownership many firearm & tactics schools have sprung up.
Keep your firearms clean & read the owners manual(s).
Use only factory made high quality brands for carry-defense ammunition.
No hand-loads or reloaded rounds for defense.
To have a plan or a legal(defense atty) system ready to go, is smart too.
For websites & firearm resources see;
www.nra.org www.gunsamerica.com www.jgsales.com www.natchezss.com www.brownells.com www.gunvideo.com www.safariland.com www.blackhawk.com www.galls.com www.uscav.com www.grafs.com www.shopcorbon.com www.handgunlaw.us www.gunlawguide.com www.boatmanbooks.com www.deltapress.com www.berettausa.com www.sigsauer.com www.smithandwesson.com www.midwayusa.com