Warpless Learning Resources
Kirua has made a beginner's guide for new Warpless runners and you can find it here.
(Rest copied from Aweglib's Pastebin: http://pastebin.com/faZyLxux)
The Warpless Route by CujoIHSV goes over basic theory, when and where to fight hammer bros and use items, etc.
Warpless Tutorial by WhenChukAttacks: https://www.twitch.tv/whenchukattacks/v/42569050
Talks about basic movement in general as well as strats for levels, good source if you've gotten a little start with SMB3 or even if you're still brand new.
Warpless Tutorial by Lawso42:
Another good tutorial, split up by worlds. Shows individual levels then breaks them down for visual cues, etc.
Warpless Strategy by Aweglib(me :P):
Part 1 Worlds 1-3: http://www.twitch.tv/aweglib/v/34984893
Part 2 Worlds 4-6: http://www.twitch.tv/aweglib/v/36519785
Part 3 Worlds 7-8: http://www.twitch.tv/aweglib/v/36520960
I wanted to make more of a big picture kind of guide, geared more towards players who have already learned strats, but might be still struggling with remembering how to deal with RNG or mistakes during a run. How to do levels quickly is shown as just part of the overall discussion, but this is focused more on handling the route instead of individual level strats.
A rom made by FredCoughlin to assist with learning the game via emulator or flash cart, it includes free movement on the overworld, a full inventory, world and lives select on the title screen, as well as some extra paths to make traversing the world map a bit easier (especially in w8).
Recently, Dots has added a few features to Fred's original ROM, including P-meter updates to help manage P-speed, the ability to Start+Select to exit levels, and more paths in World 9 (Warp Zone) to allow movement between worlds easier.
Game Genie Codes for Console:
KKKZSPIU YPXXLVGE AEUGNSSL
As far as I know these are the 3 best Game Genie codes to use if you want to practice on console. I don't know exactly which code is which, but it gives you access to a world select and life counter on the opening screen, (Up/Down to change world on the left, A to add on 5 more lives) gives you a full inventory with the ability to reuse items, as well as letting you re-enter normal stages. Forts, airships, and odd levels like the pyramid are unable to be re-enter after completion, so you'll have to suicide in the level or reset to get back into them.