Q: Exposure with A77 / Bulb mode
Theres been a few good and quick tutorials about photographing stars, check http://www.picturecorrect.com/tips/how-to-photograph-stars-2/ as an example of one on this site.
Night photography or long exposure is all about balance of exposure, aperture and ISO depending on the scene and requirements. Photographing inside your house in a suburb would include the ambient light, in the country other factors come into play. As the above vid discusses, you can do some quick tests to check what the results will be, often 10-30 seconds will show results... To start it's a matter of try and see and then as you get some experience doing it you will find the right settings for your equipment that works for the look you are wanting to achieve.
Thanks Rexel, I'll try go outside after I'm not sick anymore and will try to get this long star trail shot on where ever. That video is kinda new to me, using high ISO for exposure. But he said use high ISO to get more light and get how much stars there would be and how to adjust shutter. Lol I am thinking using high ISO on a77 with 25k would be terrible.
Sony A77 + Grip, Sony 16-50 2.8 SSM, Sony 50 1.4, Sigma 70-200 2.8 EX OS HSM, Sigma 105 2.8M EX OS HSM