Assuming you're coming from the town centre and wanting to bring a bike but not necessarily ride it to Gogarburn, then the tram is the best bet. Get off at the Gogarburn tram stop.
Ride your bike round the spiral that gets you onto the RBS Bridge and across the A8. As you come down the bridge into the site, you'll see a sign to the A8 bike path but ignore it and carry on along the pavement until you reach the roundabout at the end of the bridge. Turn right at the roundabout and take the internal road that heads west across the front of the car parks parallel with the A8.
Follow the road past the main entrance and over the Gogar Burn and look for a sign on your right for a road to the Conference Centre car park.
Ride up to the actual doors to the Conference Centre then dismount and walk your bike along the path that skirts the left edge of building. A little way along here you'll find a small cluster of Sheffield stands that you can lock it to.
...or so someone who works there assures me ;-)