Dragoooooooon
1. Talk to either of the staff in Warehouse A (I-10) in Port San d'Oria. Then talk to Novalmauge in the Bostaunieux Prison (walking between F-8 and G-8) in the basement of Chateaux Doraguille. After the cutscene, talk to Morjean in the cathedral (L-7) to start the quest.
2. Go to Shakrami Mines and find Excavation Points near bones. Use a pickaxe - つるはし - on the spot to retrieve a dragon's egg - 飛竜の卵. Return to Morjean in the Cathedral and tell him about the egg.
3. Next, go to Meriphataud Mountains and find the ??? point on the south face at the far east of Doragora's Spine (K-8). Trade the egg to this spot. After the event, return to San d'Oria and talk to Rahal in Chateaux Doraguille (H-9).
4. Go to Ghelsba Outpost, and find the Hide Door at F-10. A fight will ensue with a Dragon. A full party around level 40 should be able to beat it, but higher levels will help. When the fight is over, you can choose the name of your Wyvern from a list and the Dragoon job is also usable.
Ninja
1. Talk to Kaede in a house in Port Bastok (J-5). Then talk to Kagetora in Warehouse 1 (F-6). After that, talk to Ensetsu in the same house as Kaede (I-5) to start the quest.
2. Go to Korroloka Tunnel (you enter from Zeruhn Mines), and find the ??? point in a deep area (L-8). Examine the point and Korroloka Leech will spawn. Kill them and re-examine the ??? point to receive Strange Coral - 奇棒な珊瑚.
3. Return to Ensetsu and he tells you to take the coral to Ryoma in Norg. To get to Norg you can take the Airship to Kazham from Jeuno, go through Yuhtunga Jungle to the south-west exit, then through Sea Serpent's Grotto (follow the right wall and open a hidden door which has no target name).
4. Give the coral to Ryoma in Norg (H-8) and she will give you the "Sword which cannot be drawn" - 抜けない抜?. Take this to Ensetsu and you will be given access to the Ninja job.
Samurai
1. Talk to Jaucribaix in Norg (outside Gilgamesh's room on 2F). He wants a branch from a tree in a sacred place - ?ケ地の木の枝 - and iron filings from a bomb - ボムの卸し鉄. Talk to Ranemaud to receive a sacred tree sapling - ?_木の苗木 - then talk to Aeka to receive old iron from the east - 東方の古鉄. The next two parts can be done in any order.
2. Trade the old iron to the ??? point at the far west of Konschtat Highlands (D-8). A bomb enemy, Forger, will appear. Kill it and you will receive the iron filings. Even if you fight this bomb with a party, it will only drop item, and you can only trade iron to the ??? every 3 minutes.
3. Use an axe - まさかり - at the ??? point on the huge tree at the west side of The Sanctuary of Zi'Tah. Walking Tree enemy, Guardian Treant, will appear. Kill it and examine ??? again to receive the branch.
4. Return to Jaucribaix with these items. After you give him them, he will tell you to come back in three days - that's 3 real hours. Come back and you will receive Samurai job and an Unsigned Sword - 無銘?.
Summoner
1. First obtain Carbuncle's Ruby - カ?[バンクルの?g玉. These are dropped by leeches. It is possible that they are dropped by leeches in every area, but the most successful encounters have been with those in Qufim and Shakrami. It is, however, a rare drop, so patience is necessary.
2. Take the ruby to Heroes' House in Windurst Walls (G-4) and open the door for the quest to begin.
3. You must get the ruby to glow in the seven different colours of the rainbow: red, orange, yellow, green, blue, indigo, violet. To do this, the ruby must be subjected to seven different types of weather around Vana'Diel.
Red - scorching heat - Valkurm, Rolanberry, Meriphataud, Oztroya etc.
Orange - clear skies - most places
Yellow - sand storms - Valkurm, Tahrongi, Konschtat etc.
Green - wind - Tahrongi, Mhaura, La Theine etc.
Blue - ice - Xarcabard, Beaucedine etc.
Indigo - rain - La Theine, Pashhow, Rolanberry etc.
Violet - thunder - Konschtat, Jugner etc.
These weather effects must be present at the time you enter that zone, so if it happens while you are in a zone, exit and return quickly to see the cutscene and confirm you have got that colour.
4. After getting all the colours, take the stone to the stone circle in La Theine (G-6) and trade it to the ??? point in the centre. You will then receive Summoner job and the Carbuncle summon.
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Taken from the excellent
FFXI Resource site (who the hell runs this anyway, I wanna thank him if anyone knows). I haven't added any "personal touches" but i've done them all so if you have any questions just ask and i'll reply.