If you are planting them in trays, watch out for browning stems, they are a definite sign that you need to plant out. The best option is to get some already potted, or try the fast growing Virginian Stock. Choosing the right flowers seeds for easy success and dramatic color takes only a bit of research. Select plants that can be neglected, such as hardy annuals.
Biennials are plants that live for two years.
The first year they only put up leaves, the second, they bloom, set seed, and die. Much like canons or a round in a song, the trick to these plants is to start them in succession. Once they are established they will reseed and continue for years. Biennial seeds are best sown in autumn. Perennials are plants that can live for several years or more.