What formats does Second Life support? If .OBJ, .3DS or .LWO isn't one of them, then you'll probably need some kind or format translator - I find Ultimate Unwrap (http://www.unwrap3d.com) to be very helpful (and inexpensive).

Or you can get one of the inexpensive modelers that support lots of formats (Wings3D, Milkshape etc.)

-Will