I get my bike serviced at a shop that does a lot of commuter and touring bikes, they check over the whole bike, I let them know of my tour and they did a great job on both our bikes.
Try to find a good LBS that knows what you are planning to do and pay particular attention to your wheels, ie wheels are true and spoke tension is correct .

On my 2001 XC USA tour (Portland OR to Portland ME) the only issue I had was broken spokes, I had to get my wheels rebuilt in Conway NH.