Outdoor bonsai position:

Generally try to keep the bonsai out of a position of direct sunlight, where they receive good air circulation, relative humidity, and are in a place where they are easily accessible to you for maintenance.

Water frequently:

Generally if you keep your trees outside where rain can water them, you don’t need to worry much in the winter except in times of hot weather or little rain. In the summer you should endeavour to water your plants several times a week, and daily in very hot periods – where you should move the trees into the shade.

Fertilizers:

The most common is pellet-form (such as ‘Osmocote’). This is a slow-release fertilizer which will take care of feeding requirements for several weeks at a time and is probably the type of fertilizer most used by bonsai enthusiasts. Soluble powder and liquid feeds are also used for rapid effect over short-term periods. These are applied to the soil with a watering can and are used up relatively quickly.

Best types of plants to use for bonsai:

Trees/shrubs which are used more commonly for bonsai – and adapt quite well are evergreens such as Pine, Cypress, Camelia, Azalea, Pomegranate, Holly, Serissa, Fig (Rainforest and Mediterranean) and Cedar. Deciduous trees such as Cherry, Maple (Japanese and Trident), Zelkova and Beech are also prime candidates.

Source: http://www.bonsaisite.com/mainten1.html