I am going to be playing a 3e game soon and the GM allows Otaku. As Technomancers are my favorite Archetype in 4e I thought I would give them a shot. However, I don't really get their skills. I really hate to ask this, being new to the forums and all, but could someone stat a good Otaku for me using the priority system?

Well, you don't ask for much, do you?
Okay, well if you're going to be a 3e otaku, you're going to be a useless little freak in the physical, so I say go all in, embrace it, and be a matrix godling.
Not sure how much I can come up with, I haven't looked at any 3e books in a long time, and don't have any on me, so the big caveat is this ALL from memory.

I really don't remember much. How do Otaku work in the priority system? You take Resources priority A and get almost nothing for it, right? I'll assume that.
You'll probably need Priority B for attributes. All your matrix stats are going to be based on your mental attributes, so you want those to be maxed. Don't forget that your maximums are one higher, as well as your maximum physical stats being one lower. If you're willing to take racial minimum in all of your physical stats, your mental attribute maximums get boosted yet another point, and you get....I think it's 2 free attribute points to boot. So you're looking at, potentially 8s (plus racial mods) in your mental stats, and 1s (again, plus mods) in your physical stats. What do you get for Attributes B? 27 point? Hmmm, with those free points maybe you could get away with Attributes at C. I don't know, I don't have the books.
These will determine your Body/Evasion/Masking/Sensor ratings for your "deck". There are formulas somewhere.

For race, an Elf or a Dwarf are good. Both have bonuses to mental stats. Ork or Troll are options for making an Otaku that still has some physical ability, but you're in serious danger of sucking at everything if you try to go that route.
Skills, I don't know, take what you can get. You get some free points to put into your Access/Control/Index/File/Slave skills. These are going to determine your TN in the matrix, and you've got maximums here of one at 6, one at 5, one at 4, and two at 3, I think. Well, take your free points, and then max them out the rest of the way with skill points. I tend to favor Access (because if you can't get in, you can't do anything), then Control, and after that they're all good options. Obviously you need to max your computer/hacking/electronics I don't remember what the skill is named skill, but whatever the name of the skill that does your hacking, max it. As an otaku, I believe you've got an exception on the regular maximum of 6 and can take it up to 8. Do so.
By now you're probably out of skill points, but if you have anything to spend try to find something useful. Stealth, probably, even if you can't do much else it can help keep you from being attacked.

Anyway, in a fight your job is to keep your head down and look harmless, and use your combat pool to DODGE. You won't have much body or armor to stand between you and that D wound, so just try not to die. As you gain karma and money you'll be able to get some awesome hacker- and mental-boosting cyber/bioware.

I'm sure someone who has looked at 3e will be along shortly (or has already beaten me to the post) to give you more details.

Cool, that gives me a start.

First of all, you might want to think about whether you really want to do this. Otaku basically have to deal with the same Matrix rules as deckers, with a lot of special rules and abilities of their own added to the mix. They are also a lot more distinctive than technomancers - they are basically "a weird mix of nearly autistic street kid and sophisticated tech-head - with extremely limited life experiences." Unlike deckers, who can be decker/sammies or even decker/mages, otaku are much more solely matrix-focused. Otaku rules are in the Matrix book, so you need that book. It's not in the core rules.

But I'll walk through a rough build with you. Many ways of doing it, here's one:

For Attributes, Moon-Hawk was right. Otaku are cost-heavy and extremely limited out of the Matrix, so you might as well take the option of starting out with a base of 1 in your physical Attributes, to get a higher limit to your mental Attributes and 2 bonus points to spend on them. So Attributes will be D, since you will be putting only 1 point in each Physical Attribute, and can't put more than 6 points into each Mental Attribute. Since the D slot being taken means you can't be a dwarf, we'll take the C slot for race to be an elf, the other race that gets a mental stat bonus. For edges and flaws, which have to balance each other under the Priority system, we'll take Bonus Attribute Point, offsetting it with a mild allergy to silver, which fits an elf. Since we have two additional bonus points (from the option we chose above), we will put one additional point into each mental Attribute. Elves also get +1 Quickness and +2 Charisma.

So final Attributes will be Body: 1, Quickness: 2, Strength: 1, Charisma: 9, Intelligence: 7, and Willpower: 7. Pretty useless outside of the matrix, but that's good, in a way, since your character won't have just enough ability to decide that he can contribute to physical combat, only to find out differently.

The A slot is taken, to be an otaku. So skills and resources need to be determined. Skills of 40 would be nice, but we can get what we need with 27 points, so we'll take Resources of B instead. This gives our otaku tribe a High lifestyle, and more importantly, gives 150 more MP to spend on complex forms.

So skills now. First, otaku have special skills called channels, corresponding to the Matrix subsystems of Access, Control, Index, Files, and Slave, and used in place of operational utilities. You can have one 6, one 5, one 4, and two 3's for them. You get 8 points free (Mental Attributes/3, rounded up), so 13 skill points to get the maximum allowable starting levels for them. Here's how I would allocate them:

Access: 6
Getting in to the system is the most important part.

Control: 5
Manipulating the system is almost as important.

Index: 4
Analyzing things, or finding things.

Files: 3, Slave: 3
Dealing with data files or peripheral devices.

Obviously, it would be great to have all of them at 6 (or better), but you have to prioritize them when you're starting out.

Remaining skills - Computer: 8 (you can get it at 8, so go for it), Electronics B/R: 4, Etiquette: 2.

Now you need complex forms - you use channels for operational utilities, but these are what you use for offensive, defensive, and special utilities. You get Computer skill of 8, times 50, plus 50 more for each level that your tribe exceeds squatter level (why Resources was bought so high). So you have 550 MP to "spend" buying complex forms.

Now - otaku choose a path - cyberadepts, who get an effective +1 to their complex forms, or technoshamans, who get a -1 TN when using their channels. Both are good, but I would pick a cyberadept. You can get a lot of rating: 5 complex forms which will effectively be 6. It makes the math a lot easier when you are trying to spend 550 MP.

For example, with 550 MP, you could get Armor, Cloak, Attack (D), Sleaze, Lock-On, Shield, and Radio Link, all at rating: 5, effectively rating: 6 for a cyberadept.

All that's left now is to spend your 5,000 Nuyen in starting resources. Don't forget that you will need some kind of offline storage for paydata. You will have a datajack and an ASIST converter already, for free. Cyberware and Bioware don't affect you negatively like they do technomancers - in fact, getting things like Cerebral Boosters and Math SPU's can boost your Matrix abilities. But with your low starting resources, you will need to acquire them later, in the game.

Thanks guys!