Dear Nuwan
You are laying RCC slab for your dream house and want some instructions to be followed by you. As about MS steel bars tri to take full length, if not possible than provide proper overlap i.e. equal to 45 x dia of the bar, bars should be free from rust and have proper cover. As for concrete material cement should be fresh, sand should be coarse sand free from silt and bazri should be free from silt etc. As per water there should be 32 liter of water required for conc. Mix of 1:2:4 and 30 liter required for Mix 1:1.5:3. For more detail you should see the concrete section of construction in gharexpert.com website, some links are given below.http://www.gharexpert.com/category/1470/Cement-Concrete-0.aspx?PL=2&Estimator=http://www.gharexpert.com/articles/Cement-Concrete-1730/Mild-Steel-Bars-in-Cement-Concrete_0.aspxhttp://www.gharexpert.com/articles/Cement-Concrete-1095/What-precautions-should-taken-while-mixing-laying-cement-concrete-mix-to-required-site--0.aspxhttp://www.gharexpert.com/articles/Cement-Concrete-1096/What-quantity-water-required-cement-concrete--0.aspx