If you intend on doing your own service I’d HIGHLY recommend you invest in a quality motorcycle jack/lift. Harbor Freight has some nice ones and it won't take long for it to pay for itself if you’re doing your own wrenching. The services are easy and you’ll want to follow the service manual not the owner’s manual. Any quality JASO certified oil is fine and it won't void any warranties if you don't use Yamalube. I have 16,000 miles on mine and I run conventional Valvoline 10W40 motorcycle oil and it works great. I highly recommend running the OE Yamaha oil filter and changing it every oil change. Quality oil filters are bout $10-12 which is what the OE one is and you know the relief valve pressure settings are correct with the OE filter but not so much with aftermarket. Just keep your receipts that way you have documentation of changing the oil if there’s even a warranty issue. I’d also recommend replacing the crush washer on the oil drain bolt during oil changes. I took a filter up to Autozone to figure out what size oil filter wrench i needed.
Here's a link to the Stryker Service Manual in PDF form....this is a great resource!!
http://www.mediafire.com/download/1n2h5yjk1nlygwq/2011+VStar+1300+Stryker+LIT-11616-24-48.pdf
Here's a link on adjusting the belt tension.
http://www.yamahastarstryker.com/21-technical-discussion/2454-tightening-belt.html