Now that I got a Journeyman's Pestle and Mortar and a bit of money, I can now do the Super Potion trick. I currently have 658 Intelligence (70 with no potions) and have 5 more potions that give 33 Intelligence each.

My plan is to use the Super Potion trick to get a nice amount of money so that I can buy spells that have effects I want and make some spells of my own. I am going to then let the potions wear off so I don't break the game too badly. I am, however, getting Alchemy increases (which is a minor skill for me), so this is contributing to leveling up.

About how much work does it take to reach one of the expansion areas so I can buy a Fortify Skill spell?
(Fortify Alchemy would allow the creation of powerful potions without having to build up to it with weaker Fortify Intelligence potions.)

Of note, I leveled up and i gained enough skill just by moving around that I was able to boost Speed by 5. Of course, this will become irrelevant once I reach the point where I can keep my speed fortified for long periods of time.

I kept 10 potions of Fortify Intelligence 69 so I can continue the trick without losing all the work.

I'm not sure i understand what you mean: If you want to get to Mournhold or Solstheim, you simply follow the assassins quest to Ebonheart (Tribunal), or use the Solstheim hints (Bloodmoon).

By the way, i never found money an issue in Morrowind - or rather, the issues are how to spend the money you have (I had a 6- or 7-digit number eventually) in a meaningful way, or to find someone who has money enough to buy the really valuable stuff you find all over the place. It may be another story to get a lot of money early in the game, though, but you can get in the 4- or 5-digit range easily enough by doing some exploring and looting and using the odd merchant in Caldera.

The task is, for a character just starting out, how to get specifically to a merchant who sells Fortify Skill spells, so that I can then make fairly powerful potions to sell without going all the way through the process of making and using Fortify Intelligence potions.

Also, I have noticed one possible way to spend large amounts of money: paying people to enchant items. (Of course, you could just Fortify Enchant and then make the items yourself.)

OK. Here is a possibility I haven't tried myself. You need Tribunal.
Spoiler:
There are merchants in Mournhold who sell Fortify spells, and who also offer Spellmaker services. Whether these services are available for everyone, I don't know.
Here is a link to a list of these people: [url=http://www.uesp.net/wiki/Tribunal:Spellmaker]http://www.uesp.net/wiki/Tribunal:Spellmaker[/url]
To get there, sleep, get attacked by an assassin, kill him, report the attack to a guard who will tell you to go to an officer in Ebonheart. This guy will in turn send you to someone in the palace in Ebonheart who can get you to Mournhold, if you want. In Mournhold, simply walk around, until you find one of the merchants listed. After you have purchased whatever you like, you can stay in Mournhold or return to Ebonheart (arrival = departure place).
This works for all levels, except that I'm not certain whether or not the merchants sell everything to everyone. I have a savegame with a level 1 character in Mournhold, so I can check this out easily tonight (Europe).

If you have Tribunal the easiest way to get money early game is to farm dark brotherhood assassins for their light armor and carved ebony darts. You can hit level 8-12 w/ perfect stat boosts just abusing Balmora trainers and farming assassins for the money to pay them. (assuming you have plenty of non-major/minor skills to train.) Best part is the assassins will jump you right in the Balmora fighter's guild common beds, so you're inches from the redguard merchant/trainer with a 2000 gp limit.

If you really want a 5000 gp limit (only worthwhile if/when your personality/mercantile is high, for this gambit anyway. There are definitely items that will eat up a 5000 gp limit all on their own even if you have the personality of a ringworm), they tend to be surrounded by advanced trainers who require a rank to offer services so can't be considered for an early game boost, EXCEPT I understand the mudcrab merchant can be charmed & led to wherever you want. Not sure if NPCs aggro him as I haven't personally tried it, though, so save first in case you need to try again more carefully.

Don't forget to wear your first set of DB gear if you're a light armor specialist. It will make surviving the next ones very much easier. And if you'd still prefer the fetching of alchemy abuse for profit to the resting of abusing DB assassins, DB assassins can be a nice bridge, as Ajira in the basement of the mage guild will train your alchemy to level 48, enough for three effects visible. (Not that effects need to be visible to wind up in the potions in Morrowind, unlike Oblivion.)

Just visited the 4 guys listed in my previous post. Mehra Helas and Jeanne Andre don't offer Fortify spells at all. For the other two, you have to become a member of the Imperial Cult. Then Laurina Maria sells Fortify spells right away, while Crito Olcinius refuses to sell you any spells until your rank is high enough.

you don't need high skill in alchemy to start making money with alchemy.

you can visit the mages guild in Caldera and steal a full set of master's equipment

then go to Nalcalria of White Haven in Balmora and buy stacks of Kwama Cuttle and Fish Scales

use those you make potions of waterwalking and sell them back to Nalcalria.

repeat at will

Actually, I have another way to make money: Buying common soul gems, summoning Ancestor Ghosts and then selling the filled soul gems. Only problem (and this is something I haven't seen in any other game I've played) is the merchants not being able to afford them.

You can always use the Construction Set to give the vendors more money, so this is not a serious issue. And there are those two uncommon merchants with 5000 or 10000 drakes in the game already.

You can use the construction set to put a suit of daedric armor with enough strength enchantments to wear it in the barrel with Fargoth's ring, but then you've sort of crossed from exploitation to straight cheating. Which is absolutely fine, it's a single-player game, but it's not really what's being discussed ITT.