Both the Saga of the Greenlanders and the Saga of Eirik the Red state that lands to the west of Greenland were first sighted accidentally by sailors to Greenland who were blown off course, and both assign large roles to the sons of Eirik the Red (discoverer of Greenland) in exploring them. However, the accounts in these two sagas, which are the earliest we have, differ quite a bit beyond those two pieces of information. In the Saga of the Greenlanders, curiosity seems to have been the primary motivation. In fact, in this saga, the accidental discoverer, Bjarni Herjolfsson, is criticized for his lack of curiosity in failing to explore the hitherto-unknown lands. In that saga, Eirik's son Leif sails there intentionally to remedy this oversight. In Eirik the Red's Saga, however, it is Leif who is blown off course and discovers these lands accidentally, but does a pretty thorough job of exploring them once there. Both sagas also agree that Gudrid, the widow of another of Eirik's sons, Thorstein, traveled to Vinland with her new husband, Karlsefni. Eirik the Red's saga emphasizes that Karlsefni was a trader and merchant, and it also states that the couple brought along a lot of livestock on this journey. The Saga of the Greenlanders mentions that the first explorers brought back both produce and animal skins, and that the idea of traveling to Vinland became attractive because it was believed such a journey would lead to both wealth and fame. It specifically states that the first voyage did not carry a lot of trade goods, but mostly weapons instead.

We can infer a few things from these details. First, the opportunity for fame was one factor. The fact that the explorers took more weapons than trade goods suggests that they were not primarily interested in trading with whatever inhabitants they found there, though they were prepared for that possibility, but more interested in raiding. Taking livestock might imply that Gudrid and Karlsefni contemplated settling there, but the livestock may simply have been intended as long-term provisions that have the advantage of carrying themselves over land. Since Karlsefni was a merchant, but it seems the voyage was not intended to trade WITH the inhabitants, and it's mentioned that the first voyage brought back skins, it's likely that the travelers hoped to acquire valuable goods there for trade elsewhere.

Based on what we know about the trading activities of the Vikings in the rest of the world, it's probable that the travelers contemplated establishing a small settlement there to acquire goods for trade, which could well have included the inhabitants of Vinland since the Vikings traded slaves. The Vikings established lots of trading depots elsewhere either to sell goods or acquire them for sale elsewhere. Furs and skins were another commodity in which Vikings are known to have traded, so the mention of bringing back skins would fit. Raiding and trading tended to be complementary strategies for the Vikings, rather than mutually exclusive.

Source: Jane Smiley, ed., The Sagas of the Icelanders, Viking, 2000.