Supplements:
Not much for technos, but arguebly important things.
In Data Trails, there are the two great echoes for a such an up and coming legendary technomancer: Skinlink and FFF. Skinlink gives you direct connections to devices through touch (as technomancers have no other obviously legal way to direct connection hack things with their living persona). FFF mimics the effects of a Pain Editor (a pricey/difficult to aquire/forbidden bioware) - allowing technomancers to not suffer wound penalties when active, letting them thread complex forms more freely. There is a quality called Otaku to Technomancer that gives +2 Fade Resistance, which can be nice for threading/sprite heavy technos.
In Chrome Flesh: If using hacking skills (not complex forms), there is a piece of 'ware called Narco which gives +1 to attributes of drugs that give boosts to attributes, as well as a boost to resistance to addiction tests to drugs that you are mildly addicted to. As essence is valuable to technomancers, drugs are often a way to get bonuses, and drugs that affect mental attributes have the dual effect of increasing matrix limits (your mental attributes double as matrix attributes) and skill tests that use them. Ex. Psyche usually gives +1 to Intuition and Logic. With Narco, it gives +2 to to Intuition and Logic.
Direct Connections:
This is still unresolved on shadowrun. If you have a datajack that you pay for with essence, a case can be made that it can be used to direct connect your living persona to a device. (I don't allow it, but many GMs do. However, if you are only using Core and don't have access to skinlink, then I would allow it). You can't directly connect to a device through someone else's datajack. Remember that you might have some explaining to do if folks see you stick your datajack directly into a device to hack it (you might have to lie and say you have an implanted cyberdeck or something).
So without Skinlink, technomancers do a lot of wireless hacking (which is difficult). For devices that aren't wirelessly active, someone can put a datatap into it in order to give it wireless access.
Commlinks:
Technomancers should still carry commlinks, but you cannot form a persona through one and also use your living persona (which you need to make sprites, thread complex forms, and use your mental stats as matrix attributes). There is an echo in data trails that lets you do limited resonance-y things when forming a persona through a commlink/deck, but if you are not using supplements, I wouldn't worry about it .
Puppeteering Invite Marks:
I allow this, as it is the only resonance-y way to get access to a host. If a device is slaved to a host, and you puppeteer the device to invite three marks, you would get three marks on the device and on the host. Not everyone allows this, believing only "hacked" marks on slaved devices give you marks on a host (invited marks don't count). Remember, Puppeteering can be quite difficult, you need two net hits to succeed in this, and the device would be defending with the benefit of being slaved to a host (much more defense dice). My strategy here would be to use registered sprites to aid complex forms (giving your their level in dicepool bonus to your complex form test), and often pre-edge this test at level 1. This will keep the Fade low, add some dice, and get rid of limits. Puppeteering invite marks will likely need hits to exceed your Resonance and you will likely be taking physical fade. Keeping that Fade low keeps you in action with fewer wound penalties (they add up fast for thready technomancers).
I used to think that having marks on a host gives you marks on everything that it is connected to, but I I think I was actually mistaken. Being in a host does give you direct connection to devices attached to that host. So you can't get those three marks on a host, and then just start opening doors, turning off camera, muting security siren/etc. What it does do is let you hack those systems much easier (they defend as if you are directly connected) to get marks on them easier. Though I think it makes more sense and streamlines the matrix if marks on a host count as marks on all devices slaved to it.