1. Prepare soil. Cucumbers are heavy bearers, they require very rich soil: compost or aged manure is the best.
2. Cucumbers like warm and moist soil. If you plant seedlings on the manure heap that will help both with soil nutrition as well as soil temperature, because compost or manure is a "living organism" full of good bacteria that keep working on decomposing the material that is making the soil warm. Just water the planting bed regularly. You can cover seedlings with poly when weather is cool.
3. I used to start seeds outside when the soil becomes workable and warm (about 70 degrees F). Here in South Ontario, if I seed cucumbers directly in the soil in end of May, they will start bearing by mid July. If you want your cucs earlier you may starts seeds inside, and transplant outside later when soil gets warm.
4. Plants must be separated from each other by at least 2 feet in all directions. If you are using trellis, then you cam plant them closer, i.e. 1 foot apart.
5. When new seedlings start growing, it's a good idea to pinch off the end of the first sprout. This will encourage the plant to start branching our. More branches the plant has - more cucumbers will it bear.
6. Water plants regularly, keep them moist at all times. If plant is suffering with deficit of water it will become of bitter taste.
7. When flowers appear, you will notice that the plant has male and female flowers. Female flowers have a little cucumber trailing behind the flower. They need to be pollinated - naturally or some gardeners do that manually (for example if you grow cucumbers indoors). If you see the plant blossoms but no new cucumbers, you may try to encourage pollination by spraying flowers with sweet water ( dissolve 1 tbl spoon of sugar or any syrup in 0.5 litre of water) to attract natural pollinators (bees, flies, butterflies). Or you may try to pollinate them by hand: pinch off a male flower, cut off all petals so the only center of flower is left in your hand, then gently rub it on each female flower center. Here in South Ontario we have no shortage of natural pollinators though.
8. Add some organic matter around the plant root periodically.
9. Mulch soil around the plant's root with grass clippings, hey or other organic mulch. This will keep moisture in the soil and prevent it from drying out fast in the sun.
I would recommend to stay away from commercial mulching products, like colored bark clippings, as it can contain harmful chemicals that will be sucked in by your cucumbers and will end up in your body.