Looking for books on Swedish traders during the Viking age

There's not many books, since Scandinavian research is primarily published in articles. This is a good thing, since they share many of these articles online via academia.edu. So if you find a scholar who's writing about something you're interested in, be sure to look them up there. You might need to sign up for an account to get download access, but it's totally worth it. So where to start? A few recommendations:

Wladyslaw Duczko, Viking Rus: Studies on the Presence of Scandinavians in Eastern Europe, Northern World 12 (Leiden: Brill, 2004).
Anton Englert and Athena Trakadas, eds., Wulfstan’s Voyage: The Baltic Sea Region in the Early Viking Age as Seen from Shipboard, Maritime Culture of the North 2 (Roskilde: Viking Ship Museum, 2009).
Hans Andersson, Peter Carelli, and Lars Ergård, Visions of the Past: Trends and Traditions in Swedish Medieval Archaeology, Lund Studies in Medieval Archaeology 19, Riksantikvarieämbetet Arkeologiska undersökningar skrifter 24 (Stockholm: Almqvist & Wiksell International, 1997).
Johann Callmer, “The Influx of Oriental Beads into Europe during the 8th Century A.D.,” in Marianne Rasmussen, Ulla Lund Hansen, and Ulf Näsman, eds., Glass Beads: Cultural History, Technology, Experiment and Analogy, Studies in Technology and Culture 2 (Lejre: Historical-Archaeological Experimental Centre, 1995), 49-54.
Ingrid Gustin, “Coin Stock and Coin Circulation in Birka,” in James Graham-Campbell, Søren M. Sindbæk, and Gareth Williams, eds., Silver Economies, Monetisation and Society in Scandinavia AD 800–1100 (Aarhus: Aarhus University Press, 2011), 227-44.
Ingrid Gustin, "Islamic Coins and Eastern Contacts," in Björn Ambrosiani, ed., Excavations in the Black Earth 1990–1995. Eastern Connections Part Two: Numismatics and Metrology, Birka Studies 6 (Stockholm: Birka Project, 2004), pp. 96-120.
Kilger, Christoph, “Kaupang from Afar: Aspects of the Interpretation of Dirham Finds in Northern and Eastern Europe between the Late 8th and Early 10th Centuries,” in Dagfinn Skre, ed., Means of Exchange: Dealing with Silver in the Viking Age, Kaupang Excavation Project Publication Series 2, Norske Oldfunn 23 (Aarhus: Aarhus University Press, 2007), 199-252.
Ljungkvist, John, “Continental Imports to Scandinavia: Patterns and Changes between AD 400 and 800,” in Dieter Quast, ed., Foreigners in Early Medieval Europe: Thirteen International Studies on Early Medieval Mobility, Monographien des Römisch-Germanischen Zentralmuseums 78 (Mainz: Römish-Germanischen Zentralmuseums, 2009), 27-49.
Mateusz Bogucki, “Some Oriental Finds from the Port of Trade at Janów Pomorski (Truso), Poland.” In Cultural Interaction between East and West: Archaeology, Artefacts and Human Contacts in Northern Europe, edited by Ulf Fransson, Marie Svedin, Sophie Bergerbrant, and Fedir Androshchuk, 128–34. Stockholm Studies in Archaeology 44. Stockholm: Stockholm University, 2007.

Duczko is probably the most important of all these. Wulfstan's Voyage and perhaps also Visions of the Past are likely worth looking through their tables of contents to see if anything jumps out at you. Gustin and Kilger are both brilliant numismatists working on the Islamic coins that arrived in Sweden. There work is best read alongside Dagfinn Skre (for Kaupang in Norway) and Søren Sindbæk (for Denmark and southern Sweden), both of whom have a number of articles on academia.edu. Callmer is also a nice balance because he looks at trade beads and not just silver; his article might be the hardest to find, but your library's interlibrary loan office should be able to get it for you in a week or so. Ljungkvist works on the centuries leading into the Viking Age, which can give you some good background. And Bogucki is a vital reference point for knowing what was going on in the south Baltic.

It might help having a sense of some of the debates going into this. These archaeologists are interested in when and where connections between Scandinavia and the Orient were forged. The creation of this "Northern Arc" has long seemed like a possible consequence of Islamic conquests breaking down Mediterranean trade (although we're now skeptical of this; the breakdown preceding Islam), and the Northern Arc has also been connected to the economic and cultural renaissance that pulled Western Europe out of the Dark Ages (although we no longer think things were so simple and even resist using words like 'renaissance' and 'Dark Ages'). Underlying problems include how raiding connected to trading, whether raiding and/or trading was a grass-roots or an elite-driven affair, the role of towns and urbanization in the political and economic transformations of the age, transitions between money and barter (or bullion) economies, and cultural (including religious) or ethnic factors. So there's a ton of really big problems that remain unresolved for our understanding of this period, which makes it an exciting and lively field of research. Welcome aboard!