Grubs are the immature stages of different beetles. Many control grubs with the use of beneficial nematodes, which burrow into the grubs and essentially eat their way out. You can buy them at any garden centre and just follow the instructions on the package. Neem oil diluted and sprayed into the lawn may also work, because neem essentially disrupts the life cycles of many insects - but this may affect good and bag bugs. Grubs are usually feeding in either the spring or late summer to early fall - all depending on the grub type. If you don't know what kind of grubs you have, then do an earlier nematode application in the spring and then another one in the mid-late summer.
If you are lazy about watering, and you have a sun/shade mix, then look for grass seeds that have a combination of the following types:
Creeping Red Fescue - very drought/shade tolerant - does ok in full sun - a good low maintenance grass
Chewings Fescue - same as above bu doesn't spread as well. Mix the two together in shady areas
Tall Fescue - good for sun, and drought and heat. does ok in shade but not deep shade
Perennial Ryegrass - good for sun or shade, like a bit of moisture though
If you could find a bag of grass seed with a combination of at least 3/4 listed above it would be good. Then each type will grow where it is happy and it will also bring some versatility into your lawn. You will need to water lightly and frequently during seed germination and then once they get taller you can reduce irrigation. Water lawn if possible before 10am about once a week @ 1" water/week - use a tuna can to measure water amount.
For soil, you can use a medium quality topsoil. Essentially you will get a well draining soil that has some amount of nutrients in it - just make sure it comes from a good supplier, so it is weed free. If you are in Milton, I like Petrie's (
http://www.petrie.ca/) - they have very nice soils there. All the grass types I mentioned do well in fairly lower quality soils, so don't waste your money getting something super high in nutrients that would be better suited to flower or veggie gardens.
About once a year it would be great if you could add some topdressing of medium quality topsoil to level the lawn and add some nutrition. Leave your clippings on the lawn when you mow (returns nitrogen to the lawn) and cut the grass slightly taller at around 4" to help conserve water, produce more drought tolerant plants with deeper roots and shade the soil to reduce weed seed germination.