We have just been through this & managed with sheets ok until our blinds were ready. I didn't want to pre-order the blinds as I needed to see the house finished first to be sure about the colours.
Now as for sticking the blinds up - we have been using the 3M adhesives for putting up pictures & hooks around the house. Now in each packet of the 3M there are extra's bits of tape so I just cut these in half & used 4 halves to stick each sheet up. They held really well & once we didn't need the sheets anymore the tape comes away beautifully leaving no trace at all.
If anyone is looking for a good blind company in Melb. West we used MEM Blinds (after a recommendation from Ray). They were great, very professional, blinds were ready within the week & they were the cheapest by quite a bit.