PhotoTrendy.com SEO and PHP tune up

Greetings. I need someone to improve the performance of my website: [login to view URL] This is a website aimed at photography, where a user logs in, gets 1 free photo per day, and if a user uploads a photo, gets 2 download credits as reward. All photos are high resolution. This is a great idea but it wont get nowhere without promotion. I'm using AdSense to make some revenue, which could be more. Target is 10.000 users (with accounts activated) till the end of the year. I'm not much into SEO prices so make me an offer... we dont have much money but we want this running good, and we offer unlimited credits to who help us. We had 250 new users in one week since launch, which i think is good but I want it better. We made some email advertising which i guess is not very effective. We had loads of spam complaints and I want this website clean of reputation, if you know what I mean. We need search engine optimization. Loads of it. We also have small php problems but this may be concern of a new project posting. If bidders who see this are interested and know of PHP, you can PM me with details of experience. Happy bidding, and register on my website, it might be useful for you ;)