Starting tomorrow, I'll be taking my 6 year old nephew, who is in Kindergarten, to the library twice a week to work with him with reading and writing. He's struggling, barely being able to recognize letters. Can someone recommend some online resources that I can take a look at for worksheets and materials, as well as any really good books and workbooks I can get ahold of?

When my children were that age, they enjoyed starfall.com.  The website has many, many beginning reading and alphabet learning activities, plus numerous activities and short "books" that you can print to use when you are not at the computer.  A lot of their activities have a theme for holidays, etc. and there are activities for learning about calendars and other things there too. 

Here's a spelling website:  http://www.eduplace.com/kids/hmsv/smg

If you can spend the money (Wal-Mart has it), get the DVD by Leapfrog on Phonics (I think it is $9) ... I can still sing you the song!  My kids watched this video over and over and ad infinitum.  This was one of the best tools that really excelled them and they both were reading by five.  It was a fun way for them to learn.  It not only goes through each letter of the alphabet but gives you the phonetic sound of each so that reading is easier when they pick up those "Dick & Jane" books!

Hooked on phonics is a great program. You can also use the letter flash cards for him to feel more comfortable recognizing the letters.

My youngest dd loves to trace letters and we practice writing small words, site words. It helps build her confidence and makes her want to do more.

That is very sweet of you to help out and take him to the library.

A website that was very helpful for me in early homeschooling was learningpage.com. It's totally free, and the handwriting worksheets, especially, are very nicely done. (Look under "Basic Sheets".)

one of my favorite tv shows especialy for my kids (if u are ok with tv/dvd) is wordworld.. my girls LOVE it and it spellls everything out so its wonderful