Arduino uno AVR assembly with LEDs
Did you know that the Arduino Uno uses the Atmel ATmega328P processor?

using the ADC for analog input in assembly language

You may want to skim through Chapter "24. Analog-to-Digital Converter" of the ATmega328P datasheet.

You may want to read application note "AVR126: ADC of megaAVR in Single Ended Mode" and browse through the corresponding AVR126 example software.
(It's in the C language, but it mentions all the registers you'll need to read the ADC in your assembly language program).
(As you can tell from the ATmega328 datasheet, the ATmega88 has exactly the same ADC as the ATmega328).

"Assembler source code for the conversion of an analogue voltage to an 8-bit-number",
"AVR ASM Introduction: A moron's guide to ADC"
and
"ATmega8 ADC Example"
have a pure assembly language program for reading the ADC on a Atmel AVR chip
-- alas, on a slightly different chip that may have slightly different registers than the ATmega328P.

Good luck!