A sweater is a pretty advanced project for a first-timer: it involves shaping (increasing & decreasing) and fit is crucial.
Most people start with a garter stitch scarf to master the basics: cast on, knit stitch, joining a new ball of yarn, bind off, and weaving in ends. It's crucial to learn to keep your tension (how tight or loose you knit) consistent, as this will determine your gauge (how many stitches are in one inch).
http://knittinghelp.com has free online videos to teach you everything but the last part. Keeping your stitches even will come with practice.
Once you've mastered the basics, the easiest sweater is a top-down raglan done in the round (the body on circular needles, and double-pointed needles for the sleeves). You can try it on as you go for a perfect fit:
PS. Your local yarn store probably has knitting classes.
PPS. Here are some sites for men who knit:
Chunky sweaters? I typically just look for a sweater I like and then buy it a one or two sizes larger than what I usually wear XD I pair them with jeggings or leggings for a super comfy and casual outfit. :)
Wet Seal, Forever21, Urban Outfitters (sale or clearance section), Love Culture, and Charlotte Russe have my favorites. Also try Papaya, Delias, and Garage! :D
Just some random ones I thought were cute online:
http://www.urbanog.com/Fading-Horizon-To... (The ombre effect is really cool.)
http://www.urbanog.com/Love-Entwined-Top... (Really simple, but this could be accessorized with a scarf for long necklace or both layered together.)