I'm Going To Start Mapping Soon Any Helpful Advice I Could Get Would Be Nice!

I'm still very new to mapping so all I can say is just start by making a simple small size map using waw assets and textures. If you start out wanting a huge map with new assets, textures, guns, ect then it will become way too confusing.   Also make sure your map layout is done and its playable before you start detailing it.

I hope this helped!

also most people learn by starting of with "sniperbolts tutorial map"

as its already assembled and ready to go, then you can just expand on it

when youve got the hang of it, you can then remove "or replace" the sniperbolt stuff to your liking

If you use UGX script placer, it has a option for a "blank" map, or the "tutorial" map

Along with what everyone else has said...

Use the snap to grid function. It helps keep everything lined up and uniform. If you ever get to the point that you want to  portal, it will be very beneficial.

When you draw a brush, texture the whole thing as caulk, then select only the faces necessary to be textured and apply your texture(s). Only faces seen by the player should be textured.

Surface inspector is your friend.  Usefull to line up textures along with rotation, lmap, cap, fit, ect.

Try your best to avoid overlapping brushes. Its not "necessary" but its just good prcatice.

After you've gotten the basics down, check out BlackjackJohnnyy on youtube. His vids will teach you about terrain patches, curve patches, texture blending, portalling, and other things useful for detail.

Good luck and if you have further questions, don't be afraid to ask 

when creating your map, think about layout, that is so important, every room or area should have at least 2 way of leaving

I recommend using this .pdf made by W1NG3D (Co-Founder of UGXMods and is a crazy good mapper)  for basic rules and tips for mapping. This really helped me http://ugx-mods.com/downloads/tutorials/W1NG3D's%20Guide%20for%20Detailed%20Maps.pdf

Here is the original post made by him (the mirror link is the only link that works) - http://ugx-mods.com/forum/index.php/topic,590.0.html

Thank you guys! I will be looking into all of this today.