Generally speaking, for spring flowering bulbs ie daffodil/narcissus the early autumn months from August to october and planted at twice the pepth of the length of the bulb at 4-8in appart.
Tulips on the other hand, are best planted a little later in November up until Christmas,planting too early may result in frost damage at the roots.
Early or late varieties may differ slightly but you should be able to get more specific information from where you buy them. Good Luck Tbird+