You questions will be very difficult to answer unless you say, for example, where you are coming from, when, for how long.
You can probably answer it yourself without hoping for gentle responses. Do a search, and pour through hundreds of relevant posts. The search engine on this site continues to suck (for no apparent reason, except that it always has). Use the following format with Google: "site:horizonsunlimited.com word word word" with no quotes and the appropriate words entered.
Hope that's helpful.