Still think you should take out "cordially". Just sounds odd and too formal...

Then I suggest you use something like "completed" instead of done, the word done means the same thing, but doesnt convey the message as well.

"The" before plural may seem odd in polish vernacular, but its correct to use it in this instance.

Oh, sweet Logos... As a disclaimer - I'm neither officially qualified nor a native speaker but here's my take on the English version:

1. "I've been working with graphics for many years - what started as a hobby has become my full-time job for more than ten years."
You use "years" twice in a single sentence. Grammatically correct but poor style. How about "I've been working with graphics for a long time - what started as a hobby has become my full-time job of over ten years." ?
2. "In addition, I have experience in many other areas such as technology, computer science and marketing among others."
This reeks of marketing-ese "...and MORE !"; mostly because you follow "many others" with "among others". If you're alluding to something so much, people are bound to ask "OK - WHAT others ?".
Either go with "In addition, I have experience in many other areas, such as technology, computer science and marketing." or "In addition, I have experience in areas such as technology, computer science and marketing (among others)."
3. I feel that "with use of" works better with particular (and unique) things, rather than... variables. Would simple "using" be out of question or are you going for the "With use of this ancient artifact I was able to bend the forces of nature to my will" sort of vibe ?
4. "Multiple-page" requires a hyphen, I think. "Page" is not much of an adjective on its own...
5. "Realization" sounds awkward but I can't think of a replacement on the spot...
6. "I have proof of that" - this is not a mystery novel. You have "credentials".
7. "Cordially" belongs with words like "buńczucznie" and "krotochwilnie". It's cute and technically correct but... queer.
8. "I invite you" would be heck-of-a-lot smoother as "I encourage you".
9. "familiarize yourself" sounds a bit patronizing; It kinda suggests that the reader is initially lost or confused. How about "browse" ?
10. "(...) with just a small sampling" is pretty much "(...) z jedynie niewielką częścią". Get rid of "just".
11. "In case of enquiries"
"...break glass" xD How about "If you have any questions (...)" ?
12. "I invite you to take advantage of my services."
"Take advantage of" usually means either "scam" or "rape" (more or less) i.e.: "treat unfairly". You certainly don't want people doing that to you. Also - you've already told them to contact you a mere sentence ago. I think they got the idea ;P.

Yeah. Like, it's not even art at that point. It's reality. It's complete. It's the fullness of organization, presentation, teaching, understanding and simplification. They look like what any and every business should have in their literature and advertisements.

Do you do the photography yourself? Or are those stock? Because those shots are perfect.

Well, I agree, for me it also sounds odd, but it seems that for rest of English speaking users it's ok.

"completed" sounds much better than "undertaken" for me.

Welcome to my webpage!

Experience:

I have worked with graphics for more than ten years. It started as a hobby and later became my full-time job. I have experience in other areas such as technology, computer science, and marketing.

Currently I work on a freelance basis. I can use my client's materials or my own. I can create a variety of DTP project types and/or update and amend existing ones...anything from simple diagrams and advertisements to complicated brochures and multiple page catalogs. I try to make the end result the best realization of the client's needs. Reference letters are available upon request.

I have completed projects for individuals, as well as for institutions and corporations. Please have a look at a sample of my portfolio in the next section of this page.

Contact Info:

Please feel free to contact me with any inquiries you may have.

Your Name
Your phone number

Your Email

a hyperlink to a form they can fill out or whatever if your page offers this.

- - -

It is not clear based on this one page what exactly you offer. You work with "graphics"? That can mean a bunch of different things. The reader will not know exactly what you mean, unless they figure it out on another part of the webpage or wherever.

Also, "such as technology, computer science and marketing"...again, these words can mean about a million different things. I advise you to narrow it down to exactly what you do. A fully, bullet point list or something would help.

You are right, but hmm... time is "not defined", years are. I will need to think about.

So "many other areas" or "( )" if I've got it right.

I need to say that simple "using" was my first idea here, but "with use of" sounded little better - maybe because I like fantasy as you say? :D

"multiple page" solution was suggested by Tallima's post earlier. Hypen here would create "too long word" for me so maybe I should go back to original "multi-page" now?

:D Sounds good but I've never seen that word in such sentence construction as mine.

So how can you say "serdecznie"?

Sounds better, indeed.

It looks like nice solution.

Done.

It sounds really funny as you say. I will need to think about it.

Hmm... I do not associate "take advantage" with "scam" or "rape"...

Hmm... I think I do not feel the need to use such kind of bullet point list on intro page.

:D Isn't such webpage top-header as on mine not enough? :D

This list was only used to say "hey, you can speak to me using technical or marketing language words / shortcuts / slang and I will probably still understand you!", not to promote "hey, I can repair your PC" kind of way :)

Thanks! :D
Photography: it depends. I've noticed that most corporate clients have own materials for use, individuals - rather not.

I realize you already have the help you need, but if you want another opinion, I'll be glad to help. I am a professional ESL instructor and have lived my whole life in the USA being born in the East Coast and raised mostly in the West.

You are right, I already have probably most help I needed, but thank you for your offer! :)

I agree with everyone here that "take advantage of my services" sounds rather awkward. You may want to say something like "see what I have to offer" instead, which will sound less awkward and pique visitors' curiosity about your sevices. Also instead of saying "I currently work on a freelance basis" you can say "I currently work as a freelancer". That's more concise.

You specify the time period at the end of the sentence. I merely think you shouldn't use "years" two times while conveying basically the same bit of info...

Change the structure. The word "credentials" has the narrowest of meanings and this is precisely the sort of context where it should be used.

That's the thing - can you ? Should you ?
Maybe it's the "show, don't tell" principle (you shouldn't NEED to tell people that what you are writing/saying is "serdeczne"). Either that or apparent holes in my English education.

"taken advantage of

Main Entry:exploited  [ik-sploit] Show IPA
Part of Speech: adjective
Definition: used
Synonyms: abused, milked, oppressed, overburdened, overworked, taken advantage of"