This is something I've ever been shy around. that is, starting a new map. Like what do you always begin with? I know you usually start with making the terrain, and so forth. are there any good methods of making a map (from scratch)? Of course, starting new things has always been a phobia of mine.

Also I am wondering how you use download/use the trigger editors. Are there any good working ones you can recommend?

There are about 3 maps I'm planning on making, All UMS. If anyone here would have something to help, that'd be sweet.

If you plan to use a new system in your map, first tinker around with it and create a small testmap. I did that with my Starcraft-Maul Defense which I never finished.
After that you can make the terrain and build your map up. That map is still the map with my best terrain art...

My maps mostly grow. I never planned everything... maybe the first map where I planned something was/is my Diablo 1 map which I am currently creating.

SCMDraft's Trigger Editor works fine if you're used to the one in the Campaign Editor included with StarCraft. If you're used to a text-based editor, SCMDraft has one too. Also, a trigger duplicator may help you. I think MindArchon's one is in the DLDB somewhere.

If you want to learn the raw basics, This is a good tutorial
If you need help trying to do something with triggers, SEN is your home.
Terrain? SEN is your home.
Units? SEN is your home.

-----Be careful, though. Before you post a question, make sure you check recent posts, or the Wiki/Tutorial Database to see if your answer is there. Your post may be deleted, and people won't like you. (Don't bite the hand that feeds you.)
-----For quick questions, it may be more beneficial for you if you decide to go to the channel on Battle.net and ask someone there.
-----When you do actually post, give the most information you think is needed. Screenshots are always very nice for us. Help us help you.

We will be able to guide, teach, and help you, but we will not create the map for you. The most i've ever done for someone else's map was debug or create a test map. You will need to make the map, nobody else.
Keep in mind that the time spent on a map and the quality (Fun-ness, professionalism, and all other things that make a map good) of a map are directly related. If one goes up, the other must also. Rarely have I seen this rule be broken.

Remember, Start off small. Don't think your first map will be the ultimate creation, because it will end up being a too big of a slice for you to chew, and you'll end up just quitting out on it. I know, I've both seen it and experienced it.

There is also a thread where various members have described their map making process that you can read.

I would start with spell maps, start with an idea and see if you can do it. If you don't know about hyper triggers already, you can start by educating yourself. Other important concepts are death counters and switches. As far as map editors go, I recommend Scmdraft 2, which is the all-around best editor (and the only one still getting the rare update)- if it seems daunting at first, know that it is definitely worth familiarizing yourself with.