I would like to know my options for good trekking tours in Thailand, especially in (but not limited to) the Chiang Mai area. Not longer than a week, not too much "intense", but also not too much "touristy". Language is not a problem, so English or Thai speaking guides will do.
Amazing Thailand has much to say on the subject.
Tourist attractions throughout the country will often have a resident elephant, however serious trekkers and elephant riders will need to go to the northern regions of Thailand for a richer experience.
The cost will generally be around A$15 per person for an hour ride. A full day trekking will usually cost about $40.
For locations to do elephant trekking:
CHIANG MAI: At Chiang Dao Elephant Camp in Chiang Dao District, elephants are trained to perform for tourists and available for rides in the nearby forest. Mae Taeng Elephant Camp in Mae Taeng District, offers bamboo rafting in addition to elephant-back rides.
CHIANG RAI: Elephant riding is available at Mae Kok Elephant Camp on the bank of Mae Kok. You can take a ride through the surrounding forest and to nearby Karen hilltribe villages.
KANCHANABURI: An elephant ride through the jungle is popular with visitors to Thong Pha Phum and Sangkhlaburi. A ride can be incorporated into a longer trek featuring mountain biking and rafting.
Hope that gives you a good starting point!