Where to start?!?
Having made a good faith effort to find information about starting levels/mods both on this site and many others, I have come to this conclusion:
1) There's alot of info
2) I'm confused
As this is my first post, I feel compelled to start with a short introduction:
I'm a programmer at a webhosting company. I have a degree in Graphics Design, which basically boils down to: I have 10 hours training in 3D Studio Max and $30K debt (which means I can't afford 3D Studio Max). The very first ever FPS style game I've EVER played on a PC is Portal. I, too, was entranced by the Companion Cube, and felt the game was too short.
However, I seem to have a personal storyline for the game that is much darker and sinister than I've seen elsewhere. Maybe we can talk about that elsewhere.
Now, with that out of the way...
I (like many other people) have an idea for a Portal mod. I've read the Portal docs on the Valve community site (as many as I can find), and read just about everything I can on this site's wiki, and a few other sites. I have installed the new SDK into my Steam, and given all the programs a once over.
I'm COMPLETELY NEW to the whole level building/modding idea. I feel like I have steps 5-50 in my head... I just lack steps 1-4.
So, my opening shot at the community is this:
1) Are there some really simple tutorials on getting a level togeather for Portal (I thought I found some two weeks ago(?) but naturally forgot to bookmark them). I'm talking "See spot run" here. I can model some 3D pretty decently, but I'm a bit rusty. (3d Environments, not so much 3D people...)
2) I tried using the Source SDK to "Create A Mod", only to get an error (to the general gist that I can make Engine 1 mods with this SDK, but not Orange Box Engine mods... and as Portal is the only game I have installed this don't work). Then again, maybe I'm getting ahead of myself?
3) The eventual goal is to end up with a story based Mod, based on Portal*. I plan to build some environments for it, while getting some rooms as donations. 'Course, I want to make a playable demo first, hence 1 and 2 above.
* The story follows a test subject in the "Aperture Science Enrichment Center -- Tokyo Annex", with a completely different testing computer (I'm thinking GLaIX, a play on the type of UNIX kits made in the DOS days), and a completely different set of puzzles, but with more delving into the backstory of Aperture Science. Right now it's in the "Me and my friends think this would be cool" stage, and I plan on working the details out whilst taking care of 1 and 2 above.
To make a long post long, I'm completely new to this, and most of the stuff I've found so far assumes at least a basic level of modding knowledge, which I completely and utterly lack. All I've got is a good idea (IMHO), some fire to do it, and a willingness to learn HOW to do it. My mod idea is less "hey, this type of room would be cool" or "hey, I want to build a puzzle where you have to do a, b, and c", and more, "hey, you know what would be really cool? If the story was more like this, and you get the hints in between rooms." So, I'm not quite sure what the rooms will contain, whereas I have more ideas about what you can do outside the rooms. If that makes sense.
Anyway, can't wait to get a bit more involved around here and start making things.
First off, if you have any sort of background in 3d modeling, you probably want to forget what you've learned. I could type this huge explaination of the difference between Hammer and, say, 3DSM and how the engine does not operate the same way, but I can boil it down to one sentence. Hammer is not a 3D modeler, and does not behave in almost any way similarly. Yeah, there are primitives that you use to build geometry and make a level, but there is no deleting faces or creating splines or other 3DSM mumbo-jumbo I've forgotten.
That said, take a trip over to halfwit-2.com and interlopers.net. They are probably the best source for tutorials out there, and do have some bare-bones beginners stuff.
For question 2, you can't make a mod using Portal just yet. The SDK tools were updated, not the SDK Base, which contains the game code. When that is released (probably a few months, give or take a year), you'll be able to fire up a mod with the Portal Gun in it.
Please do not Private Message me for assistance. Post a thread if you have questions or concerns.
If you need to contact the staff privately, contact the Global Moderators via Discord.
Ahh, OK.
Yeah, I've noticed that the mapper was different 😀
So, basically, build maps now (and run them in the official Aperture Science User Developed Content Level Playing Device in the Portal game) and work on the bigger project once they've updated the Source SDK Base.
Hey DMC, welcome to the community.
I think you and I are pretty much in the same boat. Like you, I'm pretty technically literate, good at figuring out how programs work, and I'm full of ideas for Portal maps and mods. But the last time I did any mapping was so long ago that it's irrelevant. So I'm starting from Square One, but there's such a chaotic plethora of tutorials and message boards that it's hard to find Square One.
First I would advise you to manage your expectations. You're not going to be able to just spend a couple of days reading webpages and then start working on your Big Mod Idea. That's just not realistic. There's a big learning curve here, and you and I are at the bottom. Realize that it's going to take some time and effort to get up to speed. It will probably be a few weeks -- at least -- before you can really begin any meaningful work on a mod.
My plan, which you may or may not want to follow, is:
1. Get comfortable with Hammer.
2. Make some simple levels.
3. Make some more complicated levels.
4. Make some fancy levels.
5. Round up a team and start working on a mod.
And I'm on step 1. 
I advise you to start here:
http://developer.valvesoftware.com/wiki/Your_First_Map
Make a dead-simple HL2 map. Then see if you can make a dead-simple Portal map without referring back to the tutorial. Then move on to some more advanced material.
Here are some sites that other members have recommended to me:
http://www.halfwit-2.com
http://www.interlopers.net
http://www.3dbuzz.com
Hope this helps. Good luck!
Good point for the next guy who reads this topic; something that looks obvious, but may not be (it wasn't to me until just now)...
You don't need to find PORTAL tutorials, you can use any HALF-LIFE tutorials
Thanks for the tips. Consider my expectations managed 😀 I'm just glad to have a Start (that doesn't begin with "Now that that map you've made, and do this to it for something cool...)
I would highly recommend half-wit 2 (link 2 posts up)
That website is what taught me everything i needed to know to get mapping for gmod.. and then portal when it was released. The tutorials range from everything to creating a basic room to iris doors, lasers, clipping etc. highly useful on all levels.
the great thing about source SDK is that there is no great difference between mapping from gmod, half life or portal.
You just keep on trying till you run out of cake!?
We should probably stick this somewhere really obvious, for people who have done mapping/modding before its obvious that portal is technically mostly a HL2 mod, but people new to scene may not make that connection.
Hl2 tutorials will be best, but the basics have not changed since quake tbh. Having not done any source era mapping before portal, I found it easy to pick up.