That link does work, I used it myself to learn the hindi script about 8 months ago. Many of the questions asked can be rather difficult to explain, as you cant have the same mind set as English, however Ill see if I can clear a couple of things up.
Difference between ka, ki and ko. Ill start with "ko". Ko can translate to mean "to" HOWEVER, it can be used in many places and it doesnt actually have a translation. It can also kinda be used for the word "the" in English, if you are talking about a specific pronoun. OK some example:
Mujhko dudh pasand hai = I like milk - "to me milk like is"
mujhko asha hai ki tum thiik ho = I am glad that you are well = "to me happiness is that you fine are"
As I said before, it can be used to state a specific object, so instead of saying drink water in general... drink a specific glass of water.
It can also be used to suggest you have something (there are 2 other ways to show this, if you want I can explain them also)
For example: mujhko zukaam hai = i have a cold - to me cold is
Now, ka and kii (you wrote ki, but ki means "that") ka and kii essentially are used as you would use 's... so "baap ka ghar" - father's house. baap kii gadi" - father's car. you use ka, kii (or ke in the plural) depending on the gender of the following noun. (Ghar = house - male and gadi = car - female "note the word car is used more but I just used as an example). NOW in Hindi, they do not really have the word "of" like in English, instead the noun etc is switched. example - The house of Ram - would be - Ram's House.
Now, "main" essentially means "I" - main soc raha huu - I am thinking
mujhe and mujhko are the SAME, use either, it literally means "to me". I spoke a little about this above, they have a lot of different meanings.. but most simple sentences you can read as "to me" and it may make a little sense.
mujhse - ok, se = by, from, with, etc... it essentially puts all these words into one.
to mujhse = by me, from me, with me. It is used in different constructions and such as well... for example. "tum mujhse baat karte ho - you talk with me.
main ne or maine is used as the past tense.. so, you would say "I spoke" in hindi, you would say maine bola. (bol coming from the verb bolna). You just use "ne" if its in the past tense and has a sense of "ed" like in english.
This was a rather brief intro to all of them, but they all really have much deeper grammar, i could write a complete book on it.